实施盾构纠偏必须逐环,小量纠偏,必须防止过量纠偏而损坏已拼装管片和()
A.盾尾密封
B.千斤顶
C.拼装机
参考答案:A
The sun ____________. It's warm. [ ]
A. comes out
B. comes on
C. comes from
在Rt△ABC中,∠A=90°,AB=1,BC=2.在BC边上任取一点M,则∠AMB≥90°的概率为______.