64. Margaret ____ in the school marathon for charity before.
A. has never run B. never runs C. never ran D. has never been running
62.So far I ____ any of the exams at school.
A. haven't been failing B. hadn't failed C. didn't fail D. haven't failed
57. Kevin ____ his homework, but he ____ it yet.
A. has been doing/hasn't been finishing B. has done/hasn't finished C. has been doing/hasn't finished D. has done/hasn't been finishing