A.1m B.3m C.10m D.15m
A.12 B.15 C.8 D.10
A.0.3,-0.3 B.0.3,0 C.0.4,0 D.0.4,-0.2
A.水泥管塊 B.聚氯乙烯塑料管 C.鋼管 D.硬質(zhì)或半硬質(zhì)聚乙烯塑料管
A.2 B.3 C.1 D.0.5