问题描述：
直到看见妈妈,这个小孩才停止了哭泣.
The little child din't stop crying until he had seen his mother.
为什么用had seen,不用saw?
The little child din't stop crying until he had seen his mother.
为什么用had seen,不用saw?
问题解答：
我来补答展开全文阅读