A.4cm B.5cm C.3cm D.6cm
A.先换支撑后拆除 B.先支撑后换支撑 C.拆除与换支撑同时进行 D.不换支撑就拆除
A.1:0.75~1:1.00 B.1:0.50~1:0.75 C.1:0.30~1:0.75 D.1:0.30~1:0.50
A.4cm B.3cm C.6cm D.2cm
A.超负荷作业 B.快跑 C.低速行驶 D.维修