单项选择题
A.一个 B.一对 C.二对 D.三个
A.芳烃 B.环烷烃 C.烯烃 D.烷烃
A.稠环芳烃>稠环环烷烃>烯烃>烷烃 B.烯烃>稠环芳烃>稠环环烷烃>烷烃 C.烷烃>烯烃>稠环环烷烃>稠环芳烃 D.烷烃>稠环环烷烃>稠环芳烃>烯烃