机械密封的结构较为复杂,使用的特点是()
A、成本低
B、成本
C、寿命长
D、寿命短
参考答案:C
地下水位较高的深基础,渗透系数为43 m/d,当降水深度超过8 m时,宜采用( )。
A.明排水法
B.轻型井点降水
C.管井井点降水
D.喷射井点降水
- I want to buy _____ bananas, but I don't have _____ money with me. Can you lend me ______?
- Sorry, I don't have _____ either. [ ]
A. some; some; any; any
B. some; any; some; any
C. some; any; any; any
D. any; some; any; some