有机物命名 (CH3)2CHCH(CH3)3 (CH3)2CHCH2CH2CH3 (CH3CH2有机物命名 (CH3)2CHCH(CH3)3 (CH3)2CHCH2CH2CH3 (CH3CH2)2CHCH3 (CH3)3CCH2CH3 哪个主链为丁烷