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问题 选择题

0.1mol某元素的单质直接与足量氯气反应，质量增加7.1g，这种元素可能是

(    )

A．Na

B．Al

C．Fe

D．Cu

答案

答案：D

由题意可知1mol 的金属可消耗1mol（相当于71g）的氯气，由化学方程式可知铜符合条件，故选D

阅读理解

This is a story from a meeting held by some people and two things in nature. We call it the Four-Sided Talk. Let’s “listen to” everyone carefully and find out what they think.

People: We have lived on the earth since ancient times. The earth is our home. Now we regret what we have done to our home!

小题1:What’s the United Nations’ decision in the Four-Sided Talk?

A．Set an Earth Day.

B．Find out what is making the pollution.

C．Hold an international meeting.

D．Protect and love the earth.小题2:What doesn't the old tree tell us?

A．He’s afraid to be cut down some day.

B．The trees have the longest lives in the world.

C．Over-cutting teaches people a lesson.

D．People are destroying the natural environment.小题3:What will people do according to the passage?

① Over-use the resources. ② Beautify the earth.

③ Start a global group.   ④ Protect the earth.

A．①④

B．②③

C．①③

D．②④
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问答题 简答题

简述定额的分类。
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