双缸四作用往复泵如丢失一个泵阀,则少装()阀对流量影响最小。
A.吸入
B.排出
C.为带活塞杆的泵缸空间工作的
D.与C相反
参考答案:C
- How could you ________ my sister so easily in the crowd?
- Because she stood out in her red dress. [ ]
A. pick up
B. pick out
C. take up
D. take out
测电动机的温度常用酒精温度计。