m afraid i can't make it .i will be taking an exam then
What about 10 o'clock tomorrow morning I'm afraid I can't make it.I _____ then.
A.am going to take an exam B.am taking an exam
C.will be taking an exam D.am totake an exam
应该选C.为什么?A为什么不对?不是将要参加考试be going to do 么