(D)
You can not 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 seen 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. The 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 our direction. So moon light is only second hand sunlight.
When you look at a book, it sends to your eyes some of the light which 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 there were no time at all. Light reaches us from the moon, which is about 380 000 kilometers away, in only a little more than a second.
【小题1】You can see the book because .A．your eyes are close to it B．it reflects some of the sunlightC．it has light of its ownD．your eyesight can get to it【小题2】The underlined word “luminous” means . A．visibleB．all colorsC．giving off lightD．sunlight【小题3】 have light of their own.A．The sun and the moonB．The stars and the earth C．The sun and the starsD．The moon and the earth【小题4】Which of the following is true?A．All the things you can see give off light.B．Light from the book is much shorter 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.【小题5】This article is probably from .A．a science magazineB．a medical magazineC．a biographyD．a story book.B
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(答案→)B
解析：本文主要介绍光线的原理，以及人们为什么能够看见物体?是因为物体能够反射光线。
【小题1】B 细节题。根据文章第二段第一行When you look at a book, it sends to your eyes some of the light which falls on it, and you see the book.可知书本反射太阳光是人看清书的主要原因。故B正确。
【小题2】C 推理题。根据The sun, the stars, a lighted lamp are examples that can be seen by their own light. Such things are luminous.说明太阳这样的物体是发光体，该词是指发光的。故C项正确。
【小题3】C 细节题。根据文章第一段第2行The sun, the stars, a lighted lamp are examples that can be seen by their own light.可知太阳和一些恒星是发光体。故C正确。
【小题4】C 细节题。根据文章最后一段1,2行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 there were no time at all.可知光线从书本到眼睛的时间很短。好像一睁开眼睛，就能够看见一样，故C正确。
【小题5】A 推理题。本文属于科普类短文，主要介绍光线的原理，故最可能是从科学杂志里看到这样的文章。故A正确。