气动隔膜泵是一种以（）为动力。
参考答案：压缩空气
There are ________ days in a year.
A．three hundreds sixty- five
B．three hundreds and sixty-five
C．three hundred and sixty-five
D．three hundred and sixty five
当地基复杂程度为一级时，勘探点间距应是( )。
A．6～10m
B．10～15m
C．15～20m
D．20～25m
