A.1%~1% B.5%~10% C.10%~15% D.15%~20%
A.20~40° B.40~60° C.60~80° D.80~100°
A.技術(shù)簡單 B.電流較小 C.生產(chǎn)效率高 D.焊縫質(zhì)量好