The two cakes are of ________ size, but the one they bought last week was twice ________ size

of them.[ ]

A.the; the  

B. a; the

C. a; a  

D. the; a

各类避孕药的主要作用机制错误的是( )

A．短效口服避孕药——抑制排卵

B．长效避孕针——改变宫腔环境，不利于精子上游

C．避孕栓——杀精子或使其失去活力

D．探亲避孕药——抗着床

E．男用口服棉酚——阻止精子生成