钢轨硬弯矫直到位后,要保压(),松开油阀动作要缓和,以确保矫直效果。
A、2s
B、5~10s
C、10~20s
D、20~30s
参考答案:B
I don't think Jack is a man to be ____ when we are in trouble and need his help. [ ]
A. related to
B. hoped for
C. excepted from
D. relied on
铸铁设备点检定修制是()设备管理模式。