Merry________ as a secretary in the company for five years, but now she is a general manager of the company．

A．worked

B．has worked

C．is working

D．works

脑血管畸形最常见的是（）。

A.静脉畸形

B.烟雾病

C.动静脉畸形

D.海绵状血管瘤

E.毛细血管扩张症