be busy doing

The conviction of the parent was that I should be busy doing more important things rather than finding fault with an adolescent's vocabulary.

这名家长唯一确定的事情就是：我应该忙着做一些更重要的事情，而不是找一个未成年人用语方面的岔。

Means to be busy doing something.

就是指忙着做各种事情。

Since then, however, my husband started to be busy in doing his work so that he had hardly had enough time to talk with my son.

然而之后，先生开始忙于工作，几乎没有时间好儿子聊聊。

Georgina spends a lot of time pottering about the house pretending to be busy but doing nothing in particular.

乔治娜在房子里久久地跑来跑去，装出很忙的样子，但却没做什么事。

Admittedly, most of the time you will be too busy doing things to be aware of just how potent a period March and the months to come truly are for you.

事实上，你忙于各种事物而没有意识到三月对你来说多么有利，以及接下来的几个月为你准备的。

A be busy doing sth.

意为“忙于做某事”。故选A。