A.保護(hù)鋼絲不被銹蝕 B.統(tǒng)一外觀 C.使池壁達(dá)到規(guī)定厚度 D.增加鋼絲的拉力
A.100% B.90% C.80% D.70%
A.250ram B.450mm C.100ram D.500mm