· You know what M.D. means, but what does D.O. mean? What's different and what's alike between these two kinds of health care providers? The boys do do their homework after school every day. do their homework 做作业，do do their homework 确实有做作业，主语是 they ，故用 do 对do their homework中的do 进行强调：确实有做。 do和does的区别和用法区别是：do 是动词原形，用于第一人称、第三人称的复数 (I/you/we/they)。does 用于第三人称单数 (he/she/it) does 用于第三人称单数。do用于一般现在时且主语是复数we,they, He does come here every day. He did come here yesterday . We do help him . Do （务必）come on time next time. Do （务必）be careful next time. Do come in and sit down. 请进来坐吧。 以上是依据 … 接下来让我们看下help do sth.、help to do sth.和help doing sth.的用法区别： 1.后跟动词形式：help do sth.后跟动词原形，help to do sth.后跟不定式（to do），help doing sth.后跟动名词（doing） 例 … · Brain MRI is one of the tests you may have to determine the cause of headaches, dizziness, seizures, vision problems or hearing loss. This painless imaging test is used to diagnose a … · Can I swim? How do I shower? Do I need to buy different clothes? How will it affect my intimate life? Once you adjust, you'll likely find that it's possible to do many of the same activities you … Does he like animals? Did Jim come to school? 强调句： I do know it. 我确实知道。 He did make it. 他的确做到了。 【be动词】 1. be分两种： 1) 助动词be： 用于和实意动词一起，构成进行时和被动语 …
