问题描述： I have to help my mum doing housework错误在哪 1个回答 分类：英语 2014-12-01 问题解答： 我来补答 I have to I have to help my mum (to) do housework.help sb (to) do sth 帮助某人做某事 to 可有可无 展开全文阅读
