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问题 单项选择题

恢复局部通风时，只有在局部通风机及其开关附近10m以内风流中的瓦斯浓度都不超过（）%时，方可人工开启局部通风机。

A.0.2

B.0.5

C.1.0

D.2.0

答案

参考答案：B

填空题

Today I’d like to talk about how to become a (1) . Usually you have to start at the beginning. That is, you have to begin (2) of some sort on a local newspaper, a (3) , maybe on a small magazine -- work (4) . Now there aren’t that many organizations which have large numbers of foreign correspondents so you also have to (5) with that aim (6) . Another way of doing it is to work abroad, and work as (7) . That’s somebody who sells stories, and gets paid (8) , to newspapers and magazines and so on. And hoping to (9) that way, and eventually to be offered a (10) .
I don’t really know (11) are needed, but obviously a degree in modern languages or (12) would be very useful. But, a degree in itself probably wouldn’t (13) . It wouldn’t be enough to get you job. It wouldn’t (14) to make an editor decide to (15) . So it’s difficult to define the (16) . You’re going to need (17) and the ability to assimilate information (18) and then produce stories which (19) of the newspaper or radio or television station you (20) .
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选择题

如图所示，把一纸条放在嘴边，用力从纸条上方向前吹气，纸条就会向上飘起来。对此现象的分析，正确的是： 

[ ]

A、吹气时纸条所受浮力增大，所以飘起来

B、其实，上述现象不可能发生，从上方向前吹气，给纸条一个向下的力，纸条应向下运动

C、吹气时纸条上方空气流速大，流体压强小，所以飘起来

D、纸条飘起的动力和热气球升空的动力是一样的

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