题目

By the time he ______ ten, he ______ about 3,000 English words.
A. had been, had learned B. was, had been C. was, learned D. had been, learned

提问时间：2020-12-10

答案

【答案】B. was, had been【解析】by the time 1)到…时候为止 通常引导一个时间状语从句,表示“到……的时候为止”主句则表示在此时间之前某个事件已完成.值得注意的是,当从句用【过去时】时,主句通常用【过去...