英语
I____you___in Shanghai.How long have you been here? A hadn't known;are B haven't known;are C didn't know;were
C didn't know;were 表示在说话的前不知道你在上海,所以用一般过去式 如果用了A hadn't known,意思是原来以为知道,实际不知道,不妥放在这里
A.我不知道你在上海,你在那儿多久了? hadn't known,过去不知道,过去更早就到上海了,用had+动词的过去分词,即过去完成时态。
答:C recommend doing sth./ sb to do sth 建议做某事 recommend+that- clause建议…(从句用should +...详情>>