A.1/1000 B.1/500 C.3/1000 D.1/200
A.1/2 B.1/3 C.1/4 D.1/5
A.小于75°B.大于75°C.小于85°D.大于85°
A.大风 B.超载或支腿陷落 C.道路不平 D.无人指挥
A.10% B.20% C.30% D.40%
