A.0.05~0.1mm B.0.1~0.2mm C.0.2~0.25mm D.0.25~0.3mm E.0.3~0.4mm
A.砂料包埋不當 B.焊煤質(zhì)量差 C.火焰掌握不好 D.焊料放得位置不準 E.焊媒攤放面太廣
A.10% B.20% C.25% D.30% E.45%