问题描述: They are visiting their friends .they 1个回答 分类:综合 2014-10-06 问题解答: 我来补答 对括号中的部分提问:They are (visiting their friends).他们在看望朋友(What) (are) they doing?他们在做什么?显然你后面的句子中少了doing这个词 展开全文阅读