—Happy Halloween, Kitty.

—________ [ ]

A. Yes, I'm very happy.                  

B. Thanks. The same to you.

C. It's Halloween today. Everyone is happy.  

D. Why do you say so?  

后颅窝占位病变可引起下列哪种()

A.幕下疝 

B.钩回疝 

C.小脑扁桃体疝 

D.海马回疝 

E.扣带回疝