2.3 下列各结构式共代表几种化合物?用系统命名法命名。-|||-CH3 CH3-|||-a. CH3 一-CH b. CH3CHCH 2CHCHCH3-|||-CH2 -CH-CH-CH3 CH3 CH3-|||-CH3 CH3-|||-CH3 CH3 CH3-|||-C. CH3CHC HCHCHCH3 d CH3C CHCH2CHCH3-|||-CH3 CH3 CH3CHCH3-|||-CH3 CH3 CH3-|||-e. CH3CHCHCH2 CHCH3 f. CH3 -CH-CH-CH-|||-CH3 CH3 CH3 CH-CH3-|||-CH3