瓦斯比空气轻,易积聚在巷道顶部。()
参考答案:对
The article is ________ more difficult than that one, so I think I can understand it with the help of a dictionary.
A.much
B.quite
C.very
D.a little
在低压操作中,人体及其所携带工具与带电体的距离应不小于( )m。
A.0.1 B.0.2C.0.3 D.0.4