A.10% B.20% C.25% D.30% E.45%
A.10% B.20% C.25% D.30% E.35%
A.汽油空氣吹管 B.煤氣–空氣吹管 C.乙炔–氧氣吹管 D.高頻感應(yīng)鑄造機(jī) E.碳棒電弧熔金