(B)

　　Air is a colorless, tasteless and invisible (看不見的) gas that is around us. An “empty” drinking glass and an “empty” room, in fact, are not really empty. Each is filled with air. When the glass is filled with water, the water pushes the air out of the glass.

　　Air, as a gas, has no definite shape (一定的形狀), but because it is matter, it takes up (占據(jù)) space and it has weight. It is easy to prove (證明) that air is something that takes up space. Stuff a piece of dry cloth into the bottom of a glass so that it will not fall out when the glass is turned upside down. Push the upside-down(顛倒) glass, holding straight up and down, into a jar (罐) of water till the glass is completely covered. When the glass is taken out of the water, the cloth is still dry. The air inside the glass shows that it takes up space and keeps the water from coming in.

　　(　 ) 6. Air has no definite shape because _________.

　　A. it is a mixture　　B. it is a gas　　 C. it is matter　　 D. it is nothing

　　(　 ) 7. Since air is matter, it has ________.

　　A. room, and weight as well　　　　　 B. both room and shape

　　C. either room or weight　　　　　　　 D. neither shape nor weight

　　(　 ) 8. The word “stuff” means ________ in Chinese.

　　A. 撕　　　　　 B. 蓋　　　 C. 取掉　　　　D. 塞

　　(　 ) 9. To do the experiment (實(shí)驗(yàn)), we don’t have to get these things:

　　A. A piece of dry cloth.　　　 B. A piece of wet cloth.

　　C. A jar of water.　　　 　　 D. A glass and air.

　　(　 ) 10. Which of the following picture gives us the correct result of the experiment?

　　(W= water;　　A= air;　　C= cloth)

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