盘式制动闸在进行安全制动时，将全部制动力矩分（）次投入，延时制动。
A.1
B.2
C.3
D.4
参考答案：B
You've done so much work that you're ______ to pass the exam. [ ]
A. exposed
B. used
C. devoted
D. bound
熔炼铝液时空气湿度越大铝液越不容易吸气。
