A.C20 B.C25 C.C30 D.使用说明书或设计要求
A.1 B.2 C.3 D.4
A.空载 B.额定载荷 C.110%载荷 D.125额定载荷
A.15 B.20 C.25 D.30
A.130mm B.140mm C.150mm D.160mm