We are busy the final exams.
A. to prepare for
B. preparing for
C. preparing
D. preparing with
网友回答
A. to prepare for
(答案→)B. preparing for
C. preparing
D. preparing with
解析：忙于做某事后面跟动词通常写成be busy （in） doing sth，后面跟名词，通常
写成be busy with sth，表示目的后跟名词用介词for，为期末考试而准备，故
本题选B。