Put out the fire before going to bed.这句话before后面省略了主语,可是前面用的是祈使句吧?我觉着这

问题描述:

Put out the fire before going to bed.这句话before后面省略了主语,可是前面用的是祈使句吧?我觉着这
句话应该这么说:Putting out the fire before going to bed.难道这是类似于祈使句加And+一般将来时的结构?
这句话我知道没错,可是谁能给我解答下我的疑问啊?

前面就是表示祈使句,表示动作.后面却是省略了主语,因为在before后 所以加ing
就这样为什么在before后就加ing?before doing sth 做某事之前 (完全正确的用法)例句与用法 1. We must have a plan before doing any work.做任何工作前,我们必须订好计划。2. We all should warm up before doing some exercises.开始做运动前,我们都应该热身。3. He always consulted others before doing anything .他做什么事情都先和别人商量。4. Take your time to reflect before doing important things.在做重大的事情之前要从容不迫地思考一下。