What is Air Pollution?
Air pollution is a major change in air composition, caused by smoke, dust, water vapor or strange gases entering the air, causing strange odors, reduced visibility and climate change. They directly affect the health of humans as well as animals and plants on earth.
Current status of air pollution in Vietnam
Air pollution is a serious problem in the world and Vietnam is no exception. According to the annual report on the environmental performance index (EPI) conducted by the US Environmental Organization, Vietnam is one of the 10 countries with the highest air pollution levels in Asia.
 Current status of air pollution in the world
According to the 2020 State of the Global Air Report released by the Health Effects Institute (HEI) and the Institute for Health Metrics and Evaluation (IHME) at the University of Washington and the University of British Columbia on October 21, Air pollution in the world is very alarming. 
Air pollution is threatening human life 
The causes of air pollution come from many sources, there are basically two main causes: man-made and natural.
Natural causes
There are many natural causes such as volcanic eruptions, tsunamis, etc. that also pollute the air
Causes from humans (man-made)
There are many man-made causes from daily activities and agricultural production activities. Not only Vietnam but many developing countries are also experiencing this situation. Smoke and dust from exhaust pipes of factories and plants in industrial zones darken the sky. They emit CO2, CO, SO2, NOx and some other organic substances at extremely high concentrations.

1. We stayed with a host family.
2. I went on day trips.
3. They visited water parks.
4. I saw local attractions.
5. We went on a cycling tour.
6. They travelled by train.
7. They went on cultural visits.
8. We visited museums and galleries.

1. We stayed with a host family.
2. I went on day trips.
3. They visited water parks.
4. I saw local attractions.
5. We went on a cycling tour.
6. They travelled by train.
7. They went on cultural visits.
8. We visited museums and galleries

(1) general 

(2) important 

(3) invaded

(4) soldiers

(5) battle 

(6) army

(7) soldiers

(8) battles

(9) invade

(10) famous

1 general

2 important

3 invaded

4 soliders

5 battle

6 arm

7 soliders

8 battles

9 invade

10 famous

He has a red electric car and the white one is mine.

He has a red electric car and the white one is ours.

ytytyty

6. B

1. D

2. D

3. A

4. C

5. B

6. B

7. D

8. C

9. A

10. C

11. A

12. C

13. C

14. D

15. C

6. ___________ I have a new smartphone, I will pass my old one on to you.

A. Although B. As soon as C. While D. Therefore

1. Earth is the only ___________ planet in our solar system.

A. habit B. inhabitant C. habitat D. habitable

2. The computer shop is ___________ the clothes shop. We need to cross the street to get there.

A. next to B. behind C. between D. opposite

3. The teachers at our school use a __________ application to check students’ presence via our fingerprints.

A. biometric B. volumetric C. decametric D. hydrometric

4. Leon said he was having a math test __________, so he was very worried.

A. now B. then C. the next day D. tomorrow

5. Lisa looks like Susan and Naomi. She may be a cousin of __________.

A. their B. theirs C. her D. hers

6. We often use Messenger on Facebook to __________ group calls. It’s so convenient.

A. click B. make C. zoom D. dial

7. Three days of torrential rain caused a terrible ________ in many villages in Ha Tinh.

A. thunderstorm B. tornado C. cyclone D. flood

Câu I:

1. A

2. B

3. C

4. D

5. A

6. C

7. D

8. D

9. B

10. D

Câu II:

1. A

2. B

3. D

4. A

5. B

Câu III:

1. C

2. A

3. B

4. D

5. B

6. A

7. B

8. B

9. B

10. D

Câu I

1 A

2 B

3 C

4 D

5 A