Not only ____us light.

 (A)       does the sun give  (B) the sun gives 

(C) gives the sun      (D) the sun does give

Not only ______ us light, but it gives us heat.

A) the sun gives                            B) the sun has given

C) has the sun given                        D) does the sun give

You cannot see any object unless light from that object gets into your eyes. Some of the things you see give off light of their own. The sun, the stars, a lighted lamp are examples that can be ssen by their own light. Such things are luminous. Most of the things you see are not giving off light of their own. They are simply reflecting light that falls on them from the sun or some other luminous bodies. Then moon , for example , does not give off any light of its own. It is non-luminous. You see it because sunlight falls on it and some of it reflects in your direction. So moonlight is only secondhand sunlight.

When you look at a book, it sends your eyes some of the light that falls on it, and you see the book. If light could be kept out from where you are so that there would be no light for the book to reflect, then you could not see the book even with your eyes wide open.

Light travels so fast that the time in which it travels from the book you are reading to your eyes is so short as if it took no time at all. Light reaches us form the moon , which is about 380,000 kilometers away, in only a little more than a second.

You can see the book because___________.

   A. your eyes are close to it .   B. it reflects light

   C. it has light of its own      D. your eyes can get to it

The word “ reflects”  means____________.

   A. throws back              B. takes back

   C. gives off                 D. sends out

    ___________ have light of their won.

   A. the sun and the moon     B. The stars and the earth

   C. The sun and the stars     D. The moon and the earth

You cannot see any object unless light from that object gets into your eyes. Some of the things you see give off light of their own. The sun, the stars, a lighted lamp are examples that can be ssen by their own light. Such things are luminous. Most of the things you see are not giving off light of their own. They are simply reflecting light that falls on them from the sun or some other luminous bodies. Then moon , for example , does not give off any light of its own. It is non-luminous. You see it because sunlight falls on it and some of it reflects in your direction. So moonlight is only secondhand sunlight.

When you look at a book, it sends your eyes some of the light that falls on it, and you see the book. If light could be kept out from where you are so that there would be no light for the book to reflect, then you could not see the book even with your eyes wide open.

Light travels so fast that the time in which it travels from the book you are reading to your eyes is so short as if it took no time at all. Light reaches us form the moon , which is about 380,000 kilometers away, in only a little more than a second.

1.You can see the book because___________.

2.The word “ reflects”  means____________.

3.    ___________ have light of their won.

阅读理解：

　　Our sun is a star, and nine worlds move around it. Worlds like these are called planets.

　　But there are other stars, other suns. Not only thousands of them, but millions of millions. Do different stars have planets? We can see planets round our own sun. But we haven't seen any more. The stars are too far away from us. Stars give out light, but the planets don't have any light of their own. So we can't see them. They are too far and too dark.

　　Still, we can tell that some stars have planets. While a big planet goes round, it pulls its stars to one side. And sometimes we can see this. Then we know that the star has a planet.

　　For example, Barnard's Star is a small red star. And it is the quickest star in the sky. But sometimes it moves slower, and then quicker again. We have examined this star for a number of years, and now we are certain it has a planet.

1．Worlds moving around the sun are called ________.

[　　]

2．From the article we know that ________.

[　　]

A．there is only one sun in the universe

B．there are millions of millions of stars in the universe

C．every star can be seen with our eyes

D．all the stars are not very far from us

3．Though we can't see all of them still we can tell that ________.

[　　]

A．some stars have planets

B．some planets have light of their own

C．some stars give out no light

D．a big planet is moving towards its star

4．The article tells us that ________.

[　　]

A．Barnard's Star is the farthest from the earth

B．Barnard's Star gives out the strongest light

C．Barnard's Star is a small red one

D．Barnard's Star has no planet at all

5．Which of the following is true?

[　　]

A．We have examined Barnard's Star since some months ago.

B．We have no way to tell whether a star has a planet or not.

C．A planet always pushes its star away from it.

D．Barnard's Star does not always move at the same speed.