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¡¡¡¡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.ª¤

¡¡¡¡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.ª¤

¡¡¡¡72. You can see the book because .ª¤

¡¡¡¡A. your eyes are close to it

¡¡¡¡B. it reflects some of the sunlight

¡¡¡¡C. it has light of its own

¡¡¡¡D. your eyesight can get to it

¡¡¡¡73. The underlined word “luminous" means .ª¤

¡¡A. visible B. all colours

¡¡¡¡C. giving off light D.sunlightª¤

¡¡¡¡74. have light of their own.ª¤

¡¡¡¡A. The sun and the moon B. The stars and the earth ª¤

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