单项选择题
A.焊剂不干 B.焊接电流大 C.焊接电流过小 D.顶压力小
A.20%~25% B.20%~50% C.30%~50% D.30%~35%
A.5 B.6 C.10 D.12
A.94.092 B.118.92 C.128.92 D.138.92
微信扫一扫,加关注免费搜题