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问题 填空题

将一个圆底烧瓶装入适量的水，用带孔的橡皮塞塞住，橡皮塞下面挂一个小铃，孔内插一段套有橡皮管的短玻璃管，如图所示，晃动烧瓶，可听到清脆的铃声，然后把烧瓶放在酒精灯上加热，使水沸腾一段时间，看到有“白气”从橡皮管中冒出，用夹子夹住橡皮管．将烧瓶取下来，待烧瓶冷却后再晃动烧瓶，铃声响度和开始相比______（选填“变大”“变小”或“不变”）．这是因为此时瓶中的水蒸气______成水，空气变稀薄了．根据此现象可推理得出______．

答案

加热时瓶内产生较多水蒸气，停热后，水蒸气液化，瓶内气体变得稀薄，传声介质变少，所以传声效果变差，听到的响度也就变小，根据这一规律进行推理，瓶内传声的介质如果更稀薄，传声效果会更差，直到瓶内没有传声介质，则声音就不会传播，所以就听不到声音了．但最后的推理是实验条件无法达到的，只是推理，称之为理想实验法．

故答案为：变小；液化；真空不能传声．

阅读理解
If you are cycling in foreign countries, you will need to know what these traffic signs and signals mean.
1

A sign like this one means that there is a bike lane(车道). If there is such a sign，you are required to use the bike lane.
If there is not such a sign, you should ride with traffic as far to the right side of the road as possible.
2

This signal means you can cross the street along with pedestrians(行人). It has a green picture of a oerson walking instead of using the word“walk”.
3

This signal is the “don’t walk”sign. It is a picture of a red hand,
meaning you should stop. You should wait to cross the street until the green picture of the person walking is showing.
4

Car drivers and bikers must come to a complete stop at“STOP” signs.
5

A“YIELD”sign means to slow down and be ready to stop.
If there are pedestrians or vehicles in or near the crossroad, you must stop. If there is no traffic in or near the crossroad and it is safe, you may go through.
6

This signal means you are coming to a zebra crossing. Car drivers
and bikers must stop to allow people in the zebra crossing to cross the street.
7

When people are working on the roads, parts of the road are often
dug up or rough(不平整的). Be careful when yon are cycling. Rough roads could make you fall off your bike.
If you must move into the road to go around a work area，you should stop and look carefully to be sure there is no traffic coming.
8

A detour is a way of getting around a roadway that is closed. Roads are usually closed because of road work or dangerous conditions. If you must take a detour, be careful about the roads you aren’t used to.
 
小题1:What are cyclists required to do when they see the sign?
A．To ride against traffic.
B．To ride on the left side of the road.
C．To ride on the bike lane.
D．To ride on the right side of the road
小题2:Which of the following signs has the same meaning as the sign?


小题3:What should cyclists do when they see the sign?
A．They should be careful when they cycle on the rough road.
B．They should take the rough road and fall off their bikes.
C．They should move into the road to go around a work area.
D．They should take another route instead of the closed roadway.
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单项选择题

某外国商人甲在我国领域内犯重婚罪，对甲应如何处置( )

A．适用我国刑法追究其刑事责任

B．通过外交途径解决

C．适用该外国刑法追究其刑事责任

D．直接驱逐出境
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