— It’s time to go to bed Mary. — Oh Mum I won’t go to bed I have finished my homework.

问题补充：

— It’s time to go to bed, Mary.

— Oh, Mum, I won’t go to bed I have finished my homework.

A. after

B. until

C. since

D. because

答案：

A. after

(答案→)B. until

C. since

D. because

解析：考查固定短语。Not……until…....表示直到……才…….。