阅读理解。 Do you know how many stars there

题目：

阅读理解。

     Do you know how many stars there are in the universe? The answer is WANY! Our sun is one of about

100 billion stars in our galaxy, the Milky Way. But the Milky Way is just one of billions of galaxies that we

know about! Some other scientists say there are 2,000,000,000,000,000,000 stars!

     The largest star that we know about is called the Pistol Star (手枪星). The PistolStar is closer to the center

of the Milky- May than we are. Because of space dust we can't see it with the naked eye (肉眼). It's about 100

times the size of our Sun, and10,000,000 times as bright as the Sun~

     The closest star to the Earth is the Sun! The Sun is about 93 million miles away. We measure bigger

distances in space in light years, and one light year is about6,000,000,000,000 miles. Besides the Sun, Proxima

Centauri (半人马比邻座星) isthe closest star at 4.2 light years away: Some of the brightest stars are more

distant Rigel (参宿七), in the constellation Orion (猎户星座), is the seventh brightest star inthe sky but is 900

light years away. To see the faraway stars, scientists use the Hubble Space Telescope (哈勃空间望远镜).

Hubble has been stars that are 12 billion light years away!

     A star's color has a lot to do with its temperature. A blue-wbite star is very dense(密集的) and hot. When a

star becomes red, its energy has begun to fade(消失). Therefore, a star that is nearing the end of its life is

called a red giant(红巨星). Whilehumans grow smaller in old age, stars grow bigger until they die. In thefar

future, maybe our sun will become a red giant and destroy the Earth! Luckily, it'll be a longtime before we have

to think about that problem.

1. Of all. the stars, _______ is the newest to the earth.

A. the sun

B. the moon

C. the Pistol Star

D. Rigel

2. We measure bigger distance in space in _____.

A. meters

B. kilometers

C. miles

D. light years

3. Which is the seventh brightest star in the sky?

A. The sun.

B. Rigel.

C. Proxima Centauri.

D. The Pistol Star

4. If a star i.s nearing the end of its life, its color is _______.

A. blue

B. red

C. yellow

D. red and blue