BE BUSY IN 中的IN通常会省略吗

BE BUSY IN 中的IN通常会省略吗 be busy in 用法 be busy doing 是不是省略了in 应该是 be busy in doing 还有 上面两个跟be busy with 有什么区别么 be occupied in doing 中的in可省略吗 be busy in doing sth be busy doing 和 be busy in doing 的区别? 下面这句话是英语中的什么倒装句,及其语法知识?Very busy must be their thoughts while （they are 被省略了） engage in these spots书上书了这句话的主语时 （their thouths） be busy in 的用法?它和be busy doing, be busy with有什么区别? BE BUSY IN DOING 的例句 be busy doing中,有in么? 1.be busy(in )doing 2.be busy to do 3.be busy with 4.be busy for区别? sb be interesting to do sth sb be interested in doing sth 中的in可以省略吗 be busy in Ving,这样的用法是固定搭配吗?在busy后加上介词in,是英语中的固定搭配吗? be engaged in doing这里的in可以省略吗? busy的用法be busy with后面加什么词be busy in doing与be busy with doing与be busy doing有什么区别 Help sb in doing sth中的in可以省略吗?. fail in doing sth中的in能不能省略 用be busy in v-ing怎么造句