We know the sun, the earth and the moon are in the universe. We see the sun in the daytime and the
moon in the night.
     The sun is much bigger than the earth, and the earth is bigger than the moon. So the sun is the biggest
and the moon is the smallest. The earth goes round the sun day and night. It goes at 30 kilometers a
second.
     The moon is our satellite (卫星). It is also our neighbor. It goes round the earth all the time. The moon
goes at 8 kilometers a second. The moon can't give out light or heat itself, and nothing can live on it.
     Men live on the earth. It is going round itself all the time. The earth gives us lives, food, water and so
on. We must get on well with it.

根据短文内容，补全下面句子(每空一词)。

1. The sun is the b_____ of the three.
2. The e_____ is bigger than the moon, but s_____ than the sun.
3. The m_____ goes round the earth.
4. We can see the moon in the n_____.
5. Men must get on w_____ with the earth

     We know the sun, the earth and the moon are in the universe. We see the sun in the daytime and the
moon in the night.
     The sun is much bigger than the earth, and the earth is bigger than the moon. So the sun is the biggest
and the moon is the smallest. The earth goes round the sun day and night. It goes at 30 kilometers a second.
     The moon is our satellite (卫星). It is also our neighbor. It goes round the earth all the time. The moon
goes at 8 kilometers a second. The moon can't give out light or heat itself, and nothing can live on it.
     Men live on the earth. It is going round itself all the time. The earth gives us lives, food, water and so on.
We must get on well with it.
根据短文内容，补全下面句子（每空一词）。
1. The sun is the b______of the three.
2. The e______ is bigger than the moon, but s______than the sun.
3. The m______ goes round the earth.
4. We can see the moon in the n______.
5. Men must get on w______ with the earth

     We know the sun, the earth and the moon are in the universe. We see the sun in the daytime
and the moon in the night.
      The sun is much bigger than the earth, and the earth is bigger than the moon. So the sun is
the biggest and the moon is the smallest. The earth goes round the sun day and night. It does at
30 kilometers a second.
     The moon is our satellite (卫星) . It is also our neighbor. It goes round the earth all the time.
The moon goes at 8 kilometers a second. The moon can't give out light or heat itself, and nothing
can live on it.
     Men live on the earth, which is going round itself all the time.  Then the earth gives us lives, food,
water and so on. We must get on well with it.

根据短文内容和首字母，补全下面的单词。
1. The sun is the b_____ of the three.
2. The e_____ is bigger than the moon, but s____than the sun.
3. The m_____  goes round the earth.
4. We can see the moon in the n _____.
5. Men must get on w_____  with the earth.

     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