I. Read the following passage and choose the best answer.Before the invention of plastic: Before plastic, the only materials that could be molded into different shapes were clay and gla...

T

tranthuylinh

11 tháng 7 2021

I. Read the following passage and choose the best answer.Before the invention of plastic: Before plastic, the only materials that could be molded into different shapes were clay and glass. However, both of these materials are heavy and break easily. This is why plastic was a big improvement.Today, plastic is used in almost everything, from shopping bags and bottles to chairs and cars. Plastic has conquered the world. But do you know how it was first made?1862 - ParkesineThe first...

Đọc tiếp

I. Read the following passage and choose the best answer.

Before the invention of plastic: Before plastic, the only materials that could be molded into different shapes were clay and glass. However, both of these materials are heavy and break easily. This is why plastic was a big improvement.

Today, plastic is used in almost everything, from shopping bags and bottles to chairs and cars. Plastic has conquered the world. But do you know how it was first made?

1862 - Parkesine

The first man-made plastic was created by Alexander Parkes, who introduced it at the 1862 Great International Exhibition in London. It was called Parkesine, and it was made from plant materials. Once heated, it could be molded, and it held its shape when cooled. Also, it could be made colored or transparent. However, it was too expensive to produce for common use.

1866 - Celluloid

In the 19th century, billiards was so popular that a lot of elephants were being killed for their ivory, which was used to make billiard balls. So, people tried to find a substitute. A U.S. billiard ball company offered a prize of $10,000 to the person who could design the best substitute for natural ivory. In 1866, John Wesley Hyatt created Celluloid while trying to win the prize. Although he failed to win, Celluloid was later used to make many products, including false teeth, piano keys, and ping pong balls.

1909 - Bakelite

Leo Baekeland created Bakelite in 1909. Made entirely of artificial materials, it was the first true plastic. It was inexpensive, and it kept its shape when heated. Soon, it was being used in many things, including electrical products and jewelry. Since then, many other plastics have been developed.

Today - Petroleum

Today, most plastics are produced from non-natural materials made from petroleum. They are light, flexible, strong, and cheap. Despite all these advantages, there is one problem: plastic waste breaks down slowly and toxic chemicals can leak from it. Therefore, people are trying to develop less harmful plastics.

1. What is the main idea of this passage?

A. Plastic is harmful to many plants and crops.

B. New materials are currently being created to replace plastic.

C. Plastic was originally invented as a substitute for petroleum.

D. Plastic has been developed and improved over a long period of time.

2. Which item was NOT made with Celluloid?

A. ping pong balls B. billiard balls C. false teeth D. piano keys

3. Which was an advantage of Bakelite?

A. It broke down very slowly. B. It didn’t contain any chemicals.

C. It could be used to store petroleum. D. It could be heated without changing shape.

4. What can be inferred about Parkesine?

A. It wasn’t as strong as ivory. B. It could not be seen through.

C. It cost more to make than Bakelite. D. It was named after a billiard ball company.

5. Which can replace the word “produce” in line 8?

A. discover B. analyze B. introduce D. manufacture

#Tiếng anh lớp 9

2

DT

Đỗ Thanh Hải

CTVVIP

11 tháng 7 2021

1 D

2 B

3 D

4 A

5 D

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KY

Khinh Yên

11 tháng 7 2021

I. Read the following passage and choose the best answer.

Before the invention of plastic: Before plastic, the only materials that could be molded into different shapes were clay and glass. However, both of these materials are heavy and break easily. This is why plastic was a big improvement.

Today, plastic is used in almost everything, from shopping bags and bottles to chairs and cars. Plastic has conquered the world. But do you know how it was first made?

1862 - Parkesine

The first man-made plastic was created by Alexander Parkes, who introduced it at the 1862 Great International Exhibition in London. It was called Parkesine, and it was made from plant materials. Once heated, it could be molded, and it held its shape when cooled. Also, it could be made colored or transparent. However, it was too expensive to produce for common use.

1866 - Celluloid

In the 19th century, billiards was so popular that a lot of elephants were being killed for their ivory, which was used to make billiard balls. So, people tried to find a substitute. A U.S. billiard ball company offered a prize of $10,000 to the person who could design the best substitute for natural ivory. In 1866, John Wesley Hyatt created Celluloid while trying to win the prize. Although he failed to win, Celluloid was later used to make many products, including false teeth, piano keys, and ping pong balls.

1909 - Bakelite

Leo Baekeland created Bakelite in 1909. Made entirely of artificial materials, it was the first true plastic. It was inexpensive, and it kept its shape when heated. Soon, it was being used in many things, including electrical products and jewelry. Since then, many other plastics have been developed.

Today - Petroleum

Today, most plastics are produced from non-natural materials made from petroleum. They are light, flexible, strong, and cheap. Despite all these advantages, there is one problem: plastic waste breaks down slowly and toxic chemicals can leak from it. Therefore, people are trying to develop less harmful plastics.

1. What is the main idea of this passage?

A. Plastic is harmful to many plants and crops.

B. New materials are currently being created to replace plastic.

C. Plastic was originally invented as a substitute for petroleum.

D. Plastic has been developed and improved over a long period of time.

2. Which item was NOT made with Celluloid?

A. ping pong balls B. billiard balls C. false teeth D. piano keys

3. Which was an advantage of Bakelite?

A. It broke down very slowly. B. It didn’t contain any chemicals.

C. It could be used to store petroleum. D. It could be heated without changing shape.

4. What can be inferred about Parkesine?

A. It wasn’t as strong as ivory. B. It could not be seen through.

C. It cost more to make than Bakelite. D. It was named after a billiard ball company.

5. Which can replace the word “produce” in line 8?

A. discover B. analyze B. introduce D. manufacture

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LQ

Lê Quỳnh Anh

22 tháng 8 2017

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions. The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure...

Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.

The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure soil texture, the sand, silt, and clay particles are sorted out by size and weight. The weights of each size are then expressed as a percentage of the sample weight.

In the field, soil texture can be estimated by extracting a handful of sod and squeezing the damp soil into three basic shapes; cast, a lump formed by squeezing a sample in a clenched fist; thread, a pencil shape formed by rolling soil between the palms; and ribbon, a flatfish shape formed by squeezing a small sample between the thumb and index finger. The behavioral characteristics of the soil when molded into each of these shapes, if they can be formed at all, provides the basis for a general textural classification. The behavior of the soil in the hand test is determined by the amount of clay in the sample. Clay particles are highly cohesive, and when dampened, behave as a plastic. Therefore the higher the clay content in a sample, the more refined and durable the shapes into which it can be molded.

Another method of determining soil texture involves the use of devices called sediment sieves, screens built with a specified mesh size. When the soil is filtered through a group of sieves, each with a different mesh size, the particles become grouped in corresponding size categories. Each category can be weighed to make a textural determination. Although sieves work well for silt, sand, and larger particles, they are not appropriate for clay particles. Clay is far too small to sieve accurately; therefore, in soils with a high proportion of clay, the fine particles are measured on the basis of their settling velocity when suspended in water. Since clays settle so slowly, they are easily segregated from sand and silt. The water can be drawn off and evaporated, leaving a residue of clay, which can be weighed.

The author mentions “several representative handfuls” in the passage in order to show ______.

A. how small soil particles are

B. the requirements for an adequate soil farm

C. the process by which soil is weighed

D. the range of soil samples

#Mẫu giáo

1

DH

Dương Hoàn Anh

22 tháng 8 2017

Đáp án D

Tác giả đề cập “several representative handfuls” trong bài nhằm trình bày _______.

A. phần tử đất nhỏ ra sao

B. yêu cầu đối với một mảnh đất đầy đủ

C. quá trình đo trọng lượng đất

D. các loại mẫu đất

Ta có thể tìm thấy câu trả lời qua câu sau trong bài: “Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls.”

(Kết cấu là thuật ngữ dùng để mô tả các quy mô hỗn hợp theo hàng của các hạt trong một mẫu đất, điển hình là một vài nắm đất đại diện làm mẫu.) Như vậy cụm từ “several representative handfuls” được tác giả đề cập trong bài để chỉ các loại mẫu đất (the range of soil samples)

Lưu ý: range = a variety of things of a particular type (nhóm hay một loạt các vật cùng loại)

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LQ

Lê Quỳnh Anh

1 tháng 3 2017

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions. The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure...

Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.

The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure soil texture, the sand, silt, and clay particles are sorted out by size and weight. The weights of each size are then expressed as a percentage of the sample weight.

In the field, soil texture can be estimated by extracting a handful of sod and squeezing the damp soil into three basic shapes; cast, a lump formed by squeezing a sample in a clenched fist; thread, a pencil shape formed by rolling soil between the palms; and ribbon, a flatfish shape formed by squeezing a small sample between the thumb and index finger. The behavioral characteristics of the soil when molded into each of these shapes, if they can be formed at all, provides the basis for a general textural classification. The behavior of the soil in the hand test is determined by the amount of clay in the sample. Clay particles are highly cohesive, and when dampened, behave as a plastic. Therefore the higher the clay content in a sample, the more refined and durable the shapes into which it can be molded.

Another method of determining soil texture involves the use of devices called sediment sieves, screens built with a specified mesh size. When the soil is filtered through a group of sieves, each with a different mesh size, the particles become grouped in corresponding size categories. Each category can be weighed to make a textural determination. Although sieves work well for silt, sand, and larger particles, they are not appropriate for clay particles. Clay is far too small to sieve accurately; therefore, in soils with a high proportion of clay, the fine particles are measured on the basis of their settling velocity when suspended in water. Since clays settle so slowly, they are easily segregated from sand and silt. The water can be drawn off and evaporated, leaving a residue of clay, which can be weighed.

The word “fine” in the passage is closest in meaning to _____.

A. various

B. tiny

C. excellent

D. many

#Mẫu giáo

1

DH

Dương Hoàn Anh

1 tháng 3 2017

Đáp án B

Từ “fine” trong bài gần nghĩa nhất với _____.

A. phong phú

B. tí hon, cực tiểu

C. xuất sắc

D. rất nhiều

Ta thấy tính từ “fine” được dùng trong bài mang nghĩa là in small grains, pieces, or drops (ở dạng những hạt, viên hay giọt nhỏ bé).

Fine (adj) ≈ tiny (adj): nhỏ xíu

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LQ

Lê Quỳnh Anh

12 tháng 1 2019

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions. The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure...

Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.

The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure soil texture, the sand, silt, and clay particles are sorted out by size and weight. The weights of each size are then expressed as a percentage of the sample weight.

In the field, soil texture can be estimated by extracting a handful of sod and squeezing the damp soil into three basic shapes; cast, a lump formed by squeezing a sample in a clenched fist; thread, a pencil shape formed by rolling soil between the palms; and ribbon, a flatfish shape formed by squeezing a small sample between the thumb and index finger. The behavioral characteristics of the soil when molded into each of these shapes, if they can be formed at all, provides the basis for a general textural classification. The behavior of the soil in the hand test is determined by the amount of clay in the sample. Clay particles are highly cohesive, and when dampened, behave as a plastic. Therefore the higher the clay content in a sample, the more refined and durable the shapes into which it can be molded.

Another method of determining soil texture involves the use of devices called sediment sieves, screens built with a specified mesh size. When the soil is filtered through a group of sieves, each with a different mesh size, the particles become grouped in corresponding size categories. Each category can be weighed to make a textural determination. Although sieves work well for silt, sand, and larger particles, they are not appropriate for clay particles. Clay is far too small to sieve accurately; therefore, in soils with a high proportion of clay, the fine particles are measured on the basis of their settling velocity when suspended in water. Since clays settle so slowly, they are easily segregated from sand and silt. The water can be drawn off and evaporated, leaving a residue of clay, which can be weighed.

The word “dampened” in the passage is closest in meaning to _____.

A. examined

B. stretched

C. moistened

D. damaged

#Mẫu giáo

1

DH

Dương Hoàn Anh

12 tháng 1 2019

Đáp án C

Từ “dampened” trong bài gần nghĩa nhất với _______.

A. kiểm tra

B. giãn cách

C. làm ẩm

D. huỷ hoại

(to) dampen = (to) moisten: làm ẩm, ướt

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LQ

Lê Quỳnh Anh

29 tháng 3 2017

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions. The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure...

Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.

The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure soil texture, the sand, silt, and clay particles are sorted out by size and weight. The weights of each size are then expressed as a percentage of the sample weight.

In the field, soil texture can be estimated by extracting a handful of sod and squeezing the damp soil into three basic shapes; cast, a lump formed by squeezing a sample in a clenched fist; thread, a pencil shape formed by rolling soil between the palms; and ribbon, a flatfish shape formed by squeezing a small sample between the thumb and index finger. The behavioral characteristics of the soil when molded into each of these shapes, if they can be formed at all, provides the basis for a general textural classification. The behavior of the soil in the hand test is determined by the amount of clay in the sample. Clay particles are highly cohesive, and when dampened, behave as a plastic. Therefore the higher the clay content in a sample, the more refined and durable the shapes into which it can be molded.

Another method of determining soil texture involves the use of devices called sediment sieves, screens built with a specified mesh size. When the soil is filtered through a group of sieves, each with a different mesh size, the particles become grouped in corresponding size categories. Each category can be weighed to make a textural determination. Although sieves work well for silt, sand, and larger particles, they are not appropriate for clay particles. Clay is far too small to sieve accurately; therefore, in soils with a high proportion of clay, the fine particles are measured on the basis of their settling velocity when suspended in water. Since clays settle so slowly, they are easily segregated from sand and silt. The water can be drawn off and evaporated, leaving a residue of clay, which can be weighed.

The word “they” in the passage refers to _____.

A. categories

B. sieves

C. clay particles

D. larger particles

#Mẫu giáo

1

DH

Dương Hoàn Anh

29 tháng 3 2017

Đáp án C

Từ “they” trong đoạn chỉ _____.

A. các hạng mục, phân loại

B. các màng lọc

C. phân tử đất sét

D. các phân tử lớn hơn

“Since clays settle so slowly, they are easily segregated from sand and silt.”

(Do đất sét lắng xuống rất chậm, chúng có thể được tách biệt dễ dàng khỏi cát và bùn.)

Dễ thấy they là thay thế cho clays (clays particles

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LQ

Lê Quỳnh Anh

10 tháng 6 2018

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions. The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure...

Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.

The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure soil texture, the sand, silt, and clay particles are sorted out by size and weight. The weights of each size are then expressed as a percentage of the sample weight.

In the field, soil texture can be estimated by extracting a handful of sod and squeezing the damp soil into three basic shapes; cast, a lump formed by squeezing a sample in a clenched fist; thread, a pencil shape formed by rolling soil between the palms; and ribbon, a flatfish shape formed by squeezing a small sample between the thumb and index finger. The behavioral characteristics of the soil when molded into each of these shapes, if they can be formed at all, provides the basis for a general textural classification. The behavior of the soil in the hand test is determined by the amount of clay in the sample. Clay particles are highly cohesive, and when dampened, behave as a plastic. Therefore the higher the clay content in a sample, the more refined and durable the shapes into which it can be molded.

Another method of determining soil texture involves the use of devices called sediment sieves, screens built with a specified mesh size. When the soil is filtered through a group of sieves, each with a different mesh size, the particles become grouped in corresponding size categories. Each category can be weighed to make a textural determination. Although sieves work well for silt, sand, and larger particles, they are not appropriate for clay particles. Clay is far too small to sieve accurately; therefore, in soils with a high proportion of clay, the fine particles are measured on the basis of their settling velocity when suspended in water. Since clays settle so slowly, they are easily segregated from sand and silt. The water can be drawn off and evaporated, leaving a residue of clay, which can be weighed.

It can be inferred from the passage that a soil sample with little or no clay in it ________.

A. may not hold its shape when molded

B. does not have a classifiable texture

C. is not very heavy

D. does not have a durable shap

#Mẫu giáo

1

DH

Dương Hoàn Anh

10 tháng 6 2018

Đáp án A

Có thể suy ra từ đoạn văn rằng một mẫu đất có ít hoặc không có chất sét thì ______.

A. không thể giữ nguyên hình dạng khi được nặn

B. không có kết cấu định dạng được

C. không quá nặng

D. không có hình dạng bền nhất định

“The behavior of the soil in the hand test is determined by the amount of clay in the sample. Clay particles are highly cohesive, and when dampened, behave as a plastic. Therefore the higher the clay content in a sample, the more refined and durable the shapes into which it can be molded.”

(Trạng thái của đất qua thử nghiệm bằng tay được xác định qua lượng chất sét có trong mẫu. Các hạt đất sét có tính kết dính rất cao, và khi được làm ẩm thì có đặc tính như chất dẻo. Vì vậy, lượng đất sét có trong mẫu càng cao thì ta có thể nặn nó thành những hình dạng trau chuốt và giữ được lâu hơn.)

Từ đây ta có thể suy ra mẫu đất ít hoặc không có chất sét sẽ không giữ được hình dạng khi được vắt, nặn. Không thể kết luận liệu nó nhẹ hay nặng, hình dạng bền hay không và kết cấu phân loại được hay không.

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LQ

Lê Quỳnh Anh

8 tháng 1 2017

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions. The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure...

Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.

The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure soil texture, the sand, silt, and clay particles are sorted out by size and weight. The weights of each size are then expressed as a percentage of the sample weight.

In the field, soil texture can be estimated by extracting a handful of sod and squeezing the damp soil into three basic shapes; cast, a lump formed by squeezing a sample in a clenched fist; thread, a pencil shape formed by rolling soil between the palms; and ribbon, a flatfish shape formed by squeezing a small sample between the thumb and index finger. The behavioral characteristics of the soil when molded into each of these shapes, if they can be formed at all, provides the basis for a general textural classification. The behavior of the soil in the hand test is determined by the amount of clay in the sample. Clay particles are highly cohesive, and when dampened, behave as a plastic. Therefore the higher the clay content in a sample, the more refined and durable the shapes into which it can be molded.

Another method of determining soil texture involves the use of devices called sediment sieves, screens built with a specified mesh size. When the soil is filtered through a group of sieves, each with a different mesh size, the particles become grouped in corresponding size categories. Each category can be weighed to make a textural determination. Although sieves work well for silt, sand, and larger particles, they are not appropriate for clay particles. Clay is far too small to sieve accurately; therefore, in soils with a high proportion of clay, the fine particles are measured on the basis of their settling velocity when suspended in water. Since clays settle so slowly, they are easily segregated from sand and silt. The water can be drawn off and evaporated, leaving a residue of clay, which can be weighed.

It can be inferred that the names of the three basic shapes mentioned in paragraph 2 reflect ______.

A. the results of squeezing the soil

B. the way the soil is extracted

C. the need to check more than one handful

D. the difficulty of forming different shapes

#Mẫu giáo

1

DH

Dương Hoàn Anh

8 tháng 1 2017

Đáp án A

Có thể suy ra rằng tên 3 hình dáng được đề cập đến trong đoạn 2 nói đến _____.

A. kết quả của việc nhào nắn đất

B. cách chiết tách đất

C. sự cần thiết của việc kiểm tra hơn một nắm đất

D. sự khó khăn trong việc nhào nặn dáng khác nhau

“In the field, soil texture can be estimated by extracting a handful of sod and squeezing the damp soil into three basic shapes” (Ở đồng ruộng, kết cấu đất được đánh giá bằng cách chọn lấy một nắm đất ở bề mặt rồi vắt nắm đất ẩm này thành 3 hình dạng cơ bản)

Từ đây ta suy ra được rằng 3 tên gọi được đề cập là kết quả của việc nhào nắn đất nhằm xác định kết cấu của chúng.

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LQ

Lê Quỳnh Anh

12 tháng 4 2018

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions. The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure...

Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.

The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure soil texture, the sand, silt, and clay particles are sorted out by size and weight. The weights of each size are then expressed as a percentage of the sample weight.

In the field, soil texture can be estimated by extracting a handful of sod and squeezing the damp soil into three basic shapes; cast, a lump formed by squeezing a sample in a clenched fist; thread, a pencil shape formed by rolling soil between the palms; and ribbon, a flatfish shape formed by squeezing a small sample between the thumb and index finger. The behavioral characteristics of the soil when molded into each of these shapes, if they can be formed at all, provides the basis for a general textural classification. The behavior of the soil in the hand test is determined by the amount of clay in the sample. Clay particles are highly cohesive, and when dampened, behave as a plastic. Therefore the higher the clay content in a sample, the more refined and durable the shapes into which it can be molded.

Another method of determining soil texture involves the use of devices called sediment sieves, screens built with a specified mesh size. When the soil is filtered through a group of sieves, each with a different mesh size, the particles become grouped in corresponding size categories. Each category can be weighed to make a textural determination. Although sieves work well for silt, sand, and larger particles, they are not appropriate for clay particles. Clay is far too small to sieve accurately; therefore, in soils with a high proportion of clay, the fine particles are measured on the basis of their settling velocity when suspended in water. Since clays settle so slowly, they are easily segregated from sand and silt. The water can be drawn off and evaporated, leaving a residue of clay, which can be weighed.

It can be inferred from the passage that the sediment sieve has an advantage over the hand test in determining soil texture because _______

A. less training is required to use the sieve

B. the sieve allows for a more exact measure

C. the sieve can measure clay

D. using the sieve takes less time

#Mẫu giáo

1

DH

Dương Hoàn Anh

12 tháng 4 2018

Đáp án B

Có thể suy ra từ bài đọc rằng dùng màng lọc có lợi hơn thí nghiệm bằng tay trong việc xác định kết cấu đất là do ______.

A. cần ít tập huấn hơn để sử dụng được màng lọc

B. màng lọc cho ra kết quả chính xác hơn

C. màng lọc có thể đo đất sét

D. dùng màng lọc tốn ít thời gian hơn

Đọc kĩ cả bài ta rút ra kết luận: việc xác định kết cấu đất qua thử nghiệm bằng tay chỉ cho ta sự phân loại kết cấu thông thường, trong khi đó việc sử dụng màng lọc để xác định kết cấu đất có lợi thế hơn ở chỗ nó cho phép những kết quả đo lường chính xác hơn

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LQ

Lê Quỳnh Anh

24 tháng 8 2018

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions. The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure...

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Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions.

The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls. To measure soil texture, the sand, silt, and clay particles are sorted out by size and weight. The weights of each size are then expressed as a percentage of the sample weight.

In the field, soil texture can be estimated by extracting a handful of sod and squeezing the damp soil into three basic shapes; cast, a lump formed by squeezing a sample in a clenched fist; thread, a pencil shape formed by rolling soil between the palms; and ribbon, a flatfish shape formed by squeezing a small sample between the thumb and index finger. The behavioral characteristics of the soil when molded into each of these shapes, if they can be formed at all, provides the basis for a general textural classification. The behavior of the soil in the hand test is determined by the amount of clay in the sample. Clay particles are highly cohesive, and when dampened, behave as a plastic. Therefore the higher the clay content in a sample, the more refined and durable the shapes into which it can be molded.

Another method of determining soil texture involves the use of devices called sediment sieves, screens built with a specified mesh size. When the soil is filtered through a group of sieves, each with a different mesh size, the particles become grouped in corresponding size categories. Each category can be weighed to make a textural determination. Although sieves work well for silt, sand, and larger particles, they are not appropriate for clay particles. Clay is far too small to sieve accurately; therefore, in soils with a high proportion of clay, the fine particles are measured on the basis of their settling velocity when suspended in water. Since clays settle so slowly, they are easily segregated from sand and silt. The water can be drawn off and evaporated, leaving a residue of clay, which can be weighed.

During the procedure described in paragraph 3, when clay particles are placed into water they ______.

A. dissolve quickly

B. separate into different sizes

C. take some time to sink to the bottom

D. stick to the sides of the water container

#Mẫu giáo

1

DH

Dương Hoàn Anh

24 tháng 8 2018

Đáp án C

Trong quá trình được mô tả ở đoạn 3, khi đất sét được cho vào nước, chúng ______.

A. phân huỷ nhanh chóng

B. tách ra thành các kích cỡ khác nhau

C. mất một thời gian để lắng xuống

D. bám vào thành ống nước

Dựa vào câu: “Since clays settle so slowly, they are easily segregated from sand and silt.” (Do đất sét khá lâu lắng xuống, chúng có thể được tách biệt dễ dàng khỏi cát và bùn.) có thể kết luận khi cho đất sét vào nước, chúng mất một thời gian mới lắng xuống đáy.

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HT

Hà Thu

21 tháng 3 2022

I. Read the following passage and choose the best answer: Computing is now at the same stage as printing was when the first printing presses were used. Before printing presses were invented, only rich people like kings and dukes could afford to buy books. Often these people were unable to read and hadn’t enough time to learn. In any case, the books were so big that it was difficult for anyone to relax with a book as we do today. They wanted booked because they were expensive and there was...

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1