根据()，可将消费者购买行为分为习惯性购买行为，寻求多样化的购买行为，化解不协调购买行为，复杂购买行为等。

A.消费者习惯

B.供给者习惯

C.政府规制

D.参与者的介入程度

E.品牌间的差异程度

If I ______ the books on the reading list before, I would have attended the lecture.

A．would have read

B．have been reading

C．had read

D．have read