B21、B22型车,制动缸活塞行程重车位为()。
A.105~125mm
B.120~130mm
C.130~150mm
D.150~160mm
参考答案:D
—Look! The boys are playing football excitedly!
— good time they have!
A.How
B.What
C.What a
D.How a
《个人安全防护用品选配及使用要求》规定,听力防护用品必须使使用人实际接受的噪音值低于()。
A.85dB
B.70dB
C.65dB
D.90dB