https://online2.tingclass.net/lesson/shi0529/0009/9907/641.mp3
https://image.tingclass.net/statics/js/2012
in the middle of 正忙于...，在…時(shí)期
I am in the middle of some very important work.
我在忙一些重要工作呢。
Mike is in the middle of a meeting. Call him later.
麥克在開會呢，你一會再打給他吧。
