A.1/20~1/15 B.1/15~1/10 C.1/10~1/5 D.1/25~1/20
A.5% B.10% C.20% D.15%
A.運(yùn)輸重物 B.吊裝重物 C.現(xiàn)場組裝 D.進(jìn)行大件吊裝