A.XY B.X2Y C.XY2 D.XY3
A.除硫、磷雜質(zhì) B.適當降低了含碳量 C.滲進合金元素 D.改善表面的結(jié)構(gòu)性質(zhì)
A.CH3CH2CH2CH3 B.CH3CH(CH3)2 C.CH3C(CH3)3 D.(CH3)2CHCH2CH3