在井口控制盘气动控制回路中,仪表气经过()级减压后作为驱动气动补压泵的气源。
A、1
B、2
C、3
D、4
参考答案:A
The White family ________ Paris for nearly two years. They all miss their hometown very much. [ ]
A. left
B. will leave
C. have left
D. have been away from
坐标磨床主要用于()后的模具零件进行加工。