问题
选择题
下列实验基本操作(或实验注意事项)中,主要是出于实验安全考虑的是( )
A.实验剩余的药品不能放回原试剂瓶
B.可燃性气体的验纯
C.气体实验装置在实验前进行气密性检查
D.滴管不能交叉使用
答案
答案:B
下列实验基本操作(或实验注意事项)中,主要是出于实验安全考虑的是( )
A.实验剩余的药品不能放回原试剂瓶
B.可燃性气体的验纯
C.气体实验装置在实验前进行气密性检查
D.滴管不能交叉使用
答案:B
完形填空。 | ||||
In recent years, people are more and more interested in computer games in many towns and cities. A lot of small shops and restaurants along busy 1 have changed into 2 game houses in order to get more money. These places are always filled with 3 especially young boys. In the computer game houses, people 4 a lot of money playing with a computer. It's 5 for one to win against a computer, but one can make progress after 6 again and again. The 7 they lost, the more they want to win when they play computer games. And at last they even can not live 8 it. The result is that some people don't want to 9 . Instead, they play in the computer houses for hours and hours. For school boys, things are 10 . They have no mind for their lessons. When class is over, they rush to the nearby computer house. | ||||
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