A.最高點(diǎn) B.中間位置 C.最低點(diǎn)
A.立即進(jìn)行補(bǔ)焊 B.減壓后進(jìn)行補(bǔ)焊 C.抽真空后進(jìn)行補(bǔ)焊
A.2/10 B.2/100 C.2/1000