when the little boy saw her morther___,she couldn't help___A.coming;laughing B.come;to laugh C.comes; laughs D.came; laughing
问题描述：
when the little boy saw her morther___,she couldn't help___
A.coming;laughing B.come;to laugh C.comes; laughs D.came; laughing
答
选A。
saw sb doing/do主要是联系上下文语境 ，doing强调 看见当时正在做什么，do 表示看见过她做过什么。
couldn't help doing sth, 抑制不住做某事的意思
答
A see sb doing could not help doing sth
答
选A.
see sb doing 看到某人正在做某事
couldn't help doing 忍不住做某事.
当小男孩看到他母亲过来的时候,她忍不住哭了.