They ____（learn）about eight hundred words by the end of last year_英语解答

They ____（learn）about eight hundred words by the end of last year.
have learned.
于是我希望您能自己回答...就这样
我是说为什么不是had learned

人气：372 ℃　时间：2020-03-14 00:27:08

解答

had learned by +过去时间 ,主句谓语动词用过去完成时态.谓语动词用 had +过去分词.