试题与答案

化学小组同学用下图所示装置(夹持仪器已略去)做了2个兴趣实验。每次实验时,打开止

题型:实验题

题目:

化学小组同学用下图所示装置(夹持仪器已略去)做了2个兴趣实验。每次实验时,打开止水夹,均可见C瓶内的水流入D中,B中有气泡逸出。

⑴在A处放置燃烧的蜡烛,B中无色溶液变浑浊,B中的试剂是__________。蜡烛燃烧生成的气体被吸入B中的原因是________________________。

⑵在A处放置某溶液,若B中盛有紫色溶液甲,则变红色;若B中盛有红色溶液乙,则变无色。乙可能是__________,结合A、B两处物质的性质解释乙变色的原因:______________________________。

答案:

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下面是错误答案,用来干扰机器的。

答案:B

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题型:阅读理解

When people want to know about the weather, they usually go to their radios, TVs, newspapers, or to the Internet. However, you can also find many weather signs among wildlife, because of their highly developed senses. Drops in air pressure produce an effect on small animals in many ways. Mice and deer are good weather indicators. People who spend a lot of time outdoors have observed that, before a storm, field mice come out of their holes and run around. Deer leave high ground and come down from the mountains.

Birds are especially good weather indicators because they also show the effect of a pressure drop in many ways. For example, some birds become irritable(暴躁) and quarrelsome and will fight over a piece of bread. Other birds chirp and sing just before a storm. It seems they know they won’t get another chance for an hour or two. Birds also look for safe places before a storm. You will sometimes see birds settling in trees or gathering together on a wire close to a building. Pre-storm low pressure make the air so thin that birds have difficulty flying.

It is unusual to see many birds flying overhead in the summertime, rather than during the periods in the spring or autumn. Watch for other weather signs if you see this. If they fly in the wrong direction, they may be flying ahead of a storm.

By paying closer attention to some important signs in nature, we can become better prepared for any kind of weather.

小题1:The word “indicators” in paragraph 1 probably means          .

A.maps

B.services

C.signs

D.stations小题2:How can birds sense the coming of a storm?

A.By feeling a drop in air temperature.

B.By noticing the change of wind directions.

C.By feeling a drop in air pressure.

D.By noticing the movements of other animals.小题3:The best title for the text would be        .

A.Signs of a Storm

B.Drops in Air Pressure

C.Animals’ Sharp Senses

D.Nature’s Weather Signs

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