问题

The old man was seen _______ in the park at 7:00 a.m. yesterday.
A:exercise
B:exercised
C:to exercise
D:exercising
B:exercised
C:to exercise
D:exercising
正确答案是:
同类题型
_________ in some rural schools that the teacher is even unable to walk through the rows of desks.
He often plays games _____ his brothers and sisters.[ ]
I’ll never forget the day_____ the great scientist came to our school and gave us a speech.
What _____ honest girl Jill is! She always tells us _______.