问题补充:
The students the Art Festival when I passed by their school.
A. celebrate
B. were celebrating
C. will celebrate
D. have celebrated
答案:
A. celebrate
(答案→)B. were celebrating
C. will celebrate
D. have celebrated
解析:考查过去进行时,难度适中,当我经过学校是,学生正在庆祝艺术节,由passed一词可知是一般过去时,答案选B。