列车安全通过后要确认本线和邻线无列车开来时方可开放栏杆。（）
参考答案：对
Judging from _______ number of seats, ______ number of people were present at the meeting．
A．a; the
B．the; a
C．a; a
D．the; the
烘丝机旋转接头（）破裂，使得进、排汽相通，蒸汽无法进入筒内热交换板。
A、轴承
B、石墨密封环
C、波纹管
D、壳体
