水泵填料和外壳不应过热，填料完好，松紧合适，运行中不能滴水（）
参考答案：错
— How much money did you pay for the drink?
— None. It was ______.[ ]
A. easy
B. free
C. cheap
D. expensive
在装配时孔加工的方法主要有钻削或气割等。( )
