A.21.25 B.26.75 C.33.5 D.42.5
A.鍍鋅水煤氣管 B.紫銅管 C.尼龍管纜 D.被覆銅管
A.塑料管 B.20號(hào)鋼 C.1Cr18Ni9Ti耐酸不銹鋼 D.尿素級(jí)不銹鋼316L