In the old house _________ 10 years ago.
A. an old lady live
B. had old lady lived
C. lived an old lady
D. have old lady lived
查看答案
_____ a good teacher, I would study hard in the university.
A. Should I to become
B. Were I to become
C. I should become
D. Had I become
由定差减压阀和节流阀串联而成的组合阀是( )
A. 温度补偿调速阀
B. 溢流节流阀
C. 调速阀
D. 普通节流阀
在液压系统中,节流阀常用来控制调节执行元件的( )。
A. 运动方向
B. 运动速度
C. 工作压力
D. 输出力
下列压力控制阀中,阀的出油口直接通向油箱的是( )
A. 顺序阀
B. 减压阀
C. 溢流阀
D. 压力继电器