shoulddo和shouldbedoing有什么差别
shoulddo释义： 在一起 例句： The boy went home and thought about it long and hard. He asked his father what he shoulddo. 这个男孩回家苦苦思索了很久，他问自己的父亲他该做些什么。 shouldbedoing释义： 本应该在做…… 例句： If you are in any doubt as to whether you should be doing these exercises,...