A.搭接焊、幫條焊、坡口焊 B.電渣壓力焊、埋弧壓力焊 C.對焊、點焊、電弧焊 D.電渣壓力焊、埋弧壓力焊、氣壓焊
A.3% B.4% C.5% D.5.5%
A.25% B.30% C.40% D.50%