— 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

经常进行冷水浴，对人体有（）的良好效果。

A.防止动脉硬化

B.减少胆固醇沉积

C.消耗皮下脂肪

D.消除疲劳