(3).CH:CH2CH2CHCH2CHCH2CH2CH3 6-乙基-4-丙基壬烷 C2Hs CH2CH2CH3 2.命名下列化合物： CH2CH3 CH3 CH3 CH3 (1).CH:CHCH2CHCH2CH3 (2)CH3CH-CCH2CH2CH2CCH3 CH2CH2CH: CH3 CH3 C马 C CH CH (3).CHCH-CHCHCHCHCH (4).CHCHCHCH-CCHCHCHCHCHCH CH CH.CHCH CH CH CH CH3