“You ______ your teacher for help. He is kind-hearted.” “Yes. A whole day _______.”

A．can ask, will waste

B．must have asked, had wasted

C．could have asked, was wasted

D．shouldn’t have asked, would be wasted

甾体激素的基本骨架是（）

A.环戊烷并菲

B.环戊烷并多氢菲

C.环己烷并多氢菲

D.环己烷并菲

E.环庚烷并菲