问题 问答题

若不小心把气球弄破,它会发出“啪”的响声,这是因为气球的气是使劲吹进去或用打气筒压进去的,即气球里充满了压缩气体,当球破裂时,球内的压缩气体的体积会突然迅速膨胀,从而引起周围空气的急剧振动,所以发出“啪”的声音.类似的发声现象还有很多,诸如:

例1:______;

例2:______.

答案

响声的产生是由于物体的振动,气球破裂、煤气瓶爆炸、车胎爆炸的时候,内部气体从中冲出,并且压强大于外界,相当于冲击波,使周围气体发生振动产生巨响,但是物体本身不会发出太大的响声;

故答案为:车胎爆炸、煤气瓶爆炸.

单项选择题
阅读理解

If you are a visitor,you may look for the post office in a foreign country.Can you imagine (想像)how those people will tell you the way?

In the countryside of American Middle West,people will tell you,‘Go north three  miles.Turn east,and then go another two miles.’

While in Los Angeles,California,the American people have no idea of the distance on the map.‘How far is the post office?’ you ask.‘oh,’ they answer,‘it is about ten minutes by taxi from here.’But in fact,they don't know how far it is.

In Greece(希腊),a Greek will often say,‘Follow me.’Then he'll go with you through the streets of the city to the post office.

In many places, people usually say ‘Sorry,I don't know’ when they can't tell you the way.However,in Mexico(墨西哥),the people think ‘I don't know’ is not polite(有礼貌的).They usually give an answer, often a wrong one.

So you must be careful of their habits (习惯) when you are asking the way in a foreign country. 

小题1:In      ,the people don't tell you the direction but lead(引导) you to the post office.

A.Japan 

B.America

C.Greece

D.Mexico小题2:You will often lose your way in         because the people can't give you the right direction.   

A.Japan 

B.America 

C.Greece

D.Mexico小题3:The underlined word‘distance’means‘         ’ in Chinese. 

A.方向 

B.地方 

C.距离 

D.终点小题4:           countries are mentioned(提到) in the passage? 

A.Two 

B.Three 

C.Four 

D.Five小题5:What do people usually do in many places if they don't know the way? 

A.They lead you to the place. 

B.They give you a wrong answer.

C.They say nothing. 

D.They say ‘Sorry,I don't know.’