A.PT B.MT C.RT D.UT E.以上都不是
A.466cfh B.46.6cfh C.10.38cfh D.103.8cfh E.4.66cfh
A.電弧 B.熔化焊渣的電阻熱 C.消耗的導(dǎo)向管 D.a和b E.b和c