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问题 选择题

证明分子在化学反应中可分的事实是（　　）

A．打开盛浓盐酸的瓶盖，瓶口可见白雾飘逸

B．无色酚酞试液滴在烧碱溶液中显红色

C．食盐溶液受热蒸发后，有氯化钠晶体析出

D．加热红色氯化汞粉末，会产生使带火星木条复燃的气体，同时试管内壁附有银白色物质

答案

A、浓盐酸具有挥发性，打开盛浓盐酸的瓶盖瓶口可见白雾飘逸的过程中没有新物质生成，属于物理变化，故不能证明；

B、无色酚酞试液滴在烧碱溶液中显红色，是因为酚酞和OH-结合形成一种无机物，故不能证明分子在化学反应中可分；

C、食盐溶液受热蒸发后，有氯化钠晶体析出过程中没有新物质生成，属于物理变化，故不能证明．

D、加热红色氯化汞粉末生成汞和氧气，氧化汞分子受热分解成汞原子和氧原子，汞原子之间结合成金属汞，氧原子之间结合成氧分子，故能证明分子在化学反应中可分．

故选D．

阅读理解

We often hear people talking about a generation gap (代沟). The name is new,but the idea is old. Young people and their parents don’t understand each other. The world has always kept changing. During the second century after Christ a wise man said, “Bury me on my face because in a little while everything will be turned upside down.”  There has always been a gap between generations, but more people talk about it now. Old Mr. Ellis thinks he understands what has happened. “When I was a boy, I thought the world was a beautiful place. My life was very pleasant. But when I was older, I learned about people who were treated badly, people who didn’t have enough to eat. I wanted to help them, and I married a girl who wanted to help them, too. We went to meetings and talked a lot, but it didn’t seem to make much difference. ”“Our children grew up in a world at war. They didn’t know when the fighting would stop. They wanted their children to have nice clothes and toys. They didn’t want to think about the future. They thought nothing could be done about it.” “Now I have grandchildren, and they have their own ideas. They are trying to make the world better. They are trying to help other people. They’re making people listen to them. I am proud of their generation.”

小题1: The wise man mentioned in the text told people to bury him on his face so   that when everything is turned upside down he will _____.

A．lie on his stomach

B．lie on his back

C．stand quietly

D．sit in peace小题2:Which generation did NOT want to do anything to make the world a better one?

A．Mr. Ellis’ generation

B．His children’s generation

C．His grandchildren’s generation

D．None of the above.小题3: What is the writer’s attitude towards the generation gap?

A．Unacceptable.

B．Awful.

C．Funny.

D．Common.
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问答题

(四)题5-13～题5-16，根据三视图画出正等轴测图。
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