A.2.5m B.3.0m C.3.5m D.4.0m
A.1/6 B.1/5 C.1/4 D.1/3
A.質量好 B.保護環(huán)境 C.工人勞動強度高 D.施工工藝簡單 E.生產(chǎn)效率高