按《岩土工程勘察规范》(GB50021-2001)(2009版),()方法不宜测定渗透系数。()
A.压浆试验
B.压水试验
C.注水试验
D.抽水试验
参考答案:A
l didn't go to bed __ my mother came back. [ ]
A. until
B. while
C. since
D. unless
断路器的控制回路主要由三部分组成:控制开关、操动机构、控制电缆。