A.200mm B.300mm C.400mm D.500mm
A.將斷股處磨平用同材質(zhì)的綁線扎緊 B.進(jìn)行補(bǔ)強(qiáng) C.鋸斷做接頭 D.更換
A.7% B.25% C.27% D.30%