be busy at do吗 为什么课本上是I am busy at work every day.

be busy at do吗 为什么课本上是I am busy at work every day. 忙于做某事为什么要用be busy doing sth 可以用be busy to do sth吗为什么不能用to do啊 land on .land at区别?还有：be busy doing 和.be busy to do sth的不同? 有没有be busy to do sth?busy也是形容词丫!为什么?不是be adj to do You need to__(exercise)more,Do't always be at the desk busy doing your___(exercise) be busy to do sth有这个短语吗 为什么用be busy doing而不是be busy to do我觉得这个用法应该是be adj.to do 比如说be easy to do 为什么这个是be busy doing be busy with study还是be busy at study be busy with与be busy at的区别是什么? 为什么是be busy doing而不是be busy to do be busy to do 还是 be busy doing 英语be短语的总结请问有没人能总结出以be开头的短语吗?四级的,我自己总结不出来例如:be good at、be able to do sth、be busy with. 1.be busy(in )doing 2.be busy to do 3.be busy with 4.be busy for区别? busy 和busy at 有区别吗 有没有be busy to do sth. be busy at和别的介词的区别老师说有be busy at. 为什么 有的动词后加 动词ing 有的加 to do sth例如 be busy dingbe willing to do 英语翻译1.be afraid of 2.agree to do sth.3.not…at all 4.one after another 5.at last 6.at once 7.at the same time 8.at work 9.be away from 10.go away 11.make the bed 12.do one’s best 13.be busy with 14.be busy doing sth 15.by bus /car / plane 造句:be bad at sth be busy doing be busy with sth be excited about sth还有be good at sth be good for sb be late for sth be made of sth be ready to do sth become interested in