A.數(shù)量B.貫穿視場(chǎng)程度C.連續(xù)性D.寬度
A.直線截點(diǎn)法B.曲線截點(diǎn)法C.圓截點(diǎn)法D.交叉截點(diǎn)
A.焊接用鋼B.軸承鋼C.工具鋼D.彈簧鋼