井下无人值班的变电硐室必须(),并有值班人员巡回检查。
A.设灭火器材
B.关门加锁
C.设专人看守
D.设警示牌
参考答案:B
The managers were discussing the plan which they all wanted to see ______ out that month.
A. carriedB. to carryC. carryingD. carry
螺栓紧固时,各螺栓使用的拧紧力矩应一致,且对称均匀上紧。