By the time I was nine I hundreds of English words.A. had learnedB. have learnedC. has b

问题补充：

By the time I was nine ,I hundreds of English words.

A. had learned

B. have learned

C. has been learned

D. had been learned

答案：

(答案→)A. had learned

B. have learned

C. has been learned

D. had been learned

解析：句意:到我九岁的时候，我就学会几百个英语单词了。by the time 后跟从句，表示到…时候，从句中常用一般过去时，主句用过去完成时。而且I和learn 之间是主动的关系，不应该用被动语态，故C、D不对。B选项是现在完成时。故选A。