初中英语必备词组：be busy doing sth

遇见明天

be busy doing sth 忙于做某事

正因为是忙于做某事，所以可以想象为正在埋头苦干的情景，用进行时态是最合适的了。

【例句】

I'll call you later—I'm busy doing my homework.

我晚点打电话给你。我正在忙着做作业。

Mum was busy bathing the baby when the doorbell rang.

门铃响的时候，妈妈正忙着给婴儿洗澡。

Dad can't come to the phone because he is in the middle of talking to a client.

用今天学习的词组，替换划线部分，保持句意不变。