我现在不能说话——我正在做饭。

I can't talk now - I am ___in ___the ___middle ___of cooking a meal.

他正在做演示时突然断电了。

He ___was ___in ___the ___middle ___of his presentation when the power went out.

她正在做她的作业。

She is ___in ___the ___middle ___of doing her assignment.