基坑四周及栈桥临空面必须设置防护栏杆,栏杆高度不应低于()m,并且不得擅自拆除、破坏防护栏杆。
A.1
B.1.2
C.1.5
D.1.6
E.1.8
参考答案:B
Many new workers ________ and after six months they will be sent to build a new railway.[ ]
A. are being trained
B. are training
C. will train
D. will be trained
作用于事故停机的保护有哪些?