You can’t 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 the examples that can be seen by their own light．But most of the things you see are not giving off light of their own．They are just reflecting(反射)light that falls on them from the sun or some other luminous bodies．The moon，for example，doesn’t give off any light of its own．It is not 1uminous．You see it because sunlight falls on it and some of the sunlight reflects on the earth．So moonlight is only second—hand sunlight．
When you look at a book，it sends some of the light which fails on it to your eyes，and you see the book．If light could be kept out from where you’re so that there would be no light from the book to reflect．Then you couldn’t see the book even with your eyes wide open．Light travels so fast that the time in which it travels from the book you’re reading to your eyes is as short as if there were no time at time．Light reaches us from the moon，which is about 380，000 kilometres away，in only a little more than a second．
【小題1】You can see the book because________．
A．your eyes are close to itB．it reflects some of the light
C．it has light of its ownD．it is big enough to be seen
【小題2】The Chinese meaning of the world“l(fā)uminous”is close to_______．
A．閃光的B．看不見的C．發(fā)光的D．明亮的
【小題3】________has light of its own．
A．The moonB．The earthC．The sunD．The satellite of Dong Fong Hong
【小題4】Light travels about_________kilometers per second．
A．300，000B．100，000C．400，000D．190，000
【小題5】Which of the following is TRUE?
A．All the things you can see give off light．
B．Light from the book is much faster than that from the moon．
C．The moment you open your eyes，the light from the book travels to your eyes．
D．Light travels so fast that there is no time for you to read．

【小題1】B
【小題1】C
【小題1】C
【小題1】A
【小題1】C解析:
略
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