A.基本時(shí)間 B.輔助時(shí)間 C.準(zhǔn)備與終結(jié)時(shí)間
A.13.7mm B.13.8mm C.13.9mm D.14.0mm
A.Cr5MoV B.Cr12MoV C.7CrSiMnMoV D.4CrMnSiMoV