JZCJ型继电器前接点压力不小于（）mN。
A.200
B.150
C.100
D.300
参考答案：B
Tell John not to leave the house________he makes sure that all the lights are turned off.[ ]
A. unless
B. if
C. once
D. because
建国之初，我国政务院所属机构有（）个。
A．35
B．64
C．81
D．60
