I________in the house which______books and magazines.

A．am used to live;uede to keeping

B．used to live;has been used to keeping

C．have been used to living;was used to keep

D． used to live;was used to keeping

53号避孕药的主要作用机制是（）。

A.抑制排卵

B.杀灭精子

C.不利精子穿透

D.不利孕卵着床

E.杀灭卵子