"I WILL LET YOU KNOW THE ANSWER BY THE END OF THIS WEEK,” TOM SAI...

Câu 40: "I will let you know the answer by the end of this week,” Tom said to Janet.

A. Tom suggested giving Janet the answer by the end of the week.

B. Tom promised to give Janet the answer by the end of the week.

C. Tom insisted on letting Janet know the answer by the end of the week.

D. Tom offered to give Janet the answer by the end of the week.

Đọc kỹ đoạn văn sau và chọn phương án đúng (A hoặc B, C, D) cho mỗi câu từ 41 đến 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.