I_____ my homework when the door bell __
题型:选择题
问题:
I _____ my homework when the door bell _____. [ ]
A. did; rang
B. was doing; was ringing
C. did; was ring
D. was doing; rang
I _____ my homework when the door bell _____. [ ]
A. did; rang
B. was doing; was ringing
C. did; was ring
D. was doing; rang