一个英语时态题目Floodsandbadfarmingovertheyearsruinedalandthatandmadeitmiserablypoor.A.wasoncerichB.hadoncebeenrichC.haveoncebeenrichD.wasoncebeingrich选哪个,详细讲下为什么

Question

一个英语时态题目
Floods and bad farming over the years ruined a land that ______ and made it miserably poor.
A.was once rich B.had once been rich C.have once been rich D.was once being rich
选哪个,详细讲下为什么

Answer 1

答案：B　　解析：had been 发生在过去时（ruined）之前,故用过去完成时,如：He sang a song that had been popular for a long time.