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.
但当我正在旅行时,我收到了另一封电子邮件。
But while I ___was ___in ___the ___middle ___of my tour, I received another e-mail.
她正在写报告。
She ___is ___in ___the ___middle ___of writing a report.