Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50. The Sun today is a yellow dwarf star. It is fueled by thermonuclear reactions near its center that convert hydrogen to helium. The Sun has existed in its present state for about four billion six hundred million years and is thousands of times larger than the Earth. By studying other stars, astronomers can predict what the rest of...
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Read the following passage on transport, and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.
The Sun today is a yellow dwarf star. It is fueled by thermonuclear reactions near its center that convert hydrogen to helium. The Sun has existed in its present state for about four billion six hundred million years and is thousands of times larger than the Earth.
By studying other stars, astronomers can predict what the rest of the Sun’s life will be like. About five billion years from now, the core of the Sun will shrink and become hotter. The surface temperature will fall. The higher temperature of the center will increase the rate of thermonuclear reactions. The outer regions of the Sun will expand approximately 35 million miles, about the distance to Mercury, which is the closest planet to the Sun. The Sun will then be a red giant star. Temperatures on the Earth will become too high for life to exist.
Once the Sun has used up its thermonuclear energy as a red giant, it will begin to shrink. After it shrinks to the size of the Earth, it will become a white dwarf star. The Sun may throw off huge amounts of gases in violent eruptions called nova explosions as it changes from a red giant to a white dwarf.
After billions of years as a white dwarf, the Sun will have used up all its fuel and will have lost its heat. Such a star is called a black dwarf. After the Sun has become a black dwarf, the Earth will be dark and cold. If any atmosphere remains there, it will have frozen over the Earth’s surface.
As a white dwarf, the Sun will be _______.
A. a cool and habitable planet
B. the same size as the planet Mercury
C. thousands of times smaller than it is today
D. around 35 million miles in diameter
Hi! My name is Nam.In 2030, I will live in Viet Nam, on the one hundred and fifty-second floor of a tall aparment building. It will have a shiny white surface on the outside to reflect the sunlight and to keep it cool. On the inside, I will have central air conditionding. The big screen for me to watch movies will also be a fish tank. When it is switched off, I can see my pet fish swimming happily in it.
I will own a sky restaurant. My restaurant will be mid air. My customers will take a special lift in a capsule to enter my restaurant.
In 2030, Viet Nam will still be a beautiful country. However, the grassanf trees are unlike those today. They will be mostly in shades of yellow or brown. Life in this time will not appear too different from today, except that the weather will become hotter.
1. Which floor of the apartment will Nam live?
He will live fifty-second floor of a tall aparment building.
2. Why will the building have a shiny white surface on the outside?
To reflect the sunlight and to keep it cool.
3. What will Nam have on the inside?
On the inside,he will have central air conditionding.
4. How will customers enter Nam is restaurant?
his customers will take a special lift in a capsule to enter his restaurant.
5. What will grass and trees in 2030 be like?
They will be mostly in shades of yellow or brown.