When I went to say goodbye to Ann, she ______ the piano.

A．plays

B．played

C．has played

D．was playing

引起子痫抽搐的主要病理原因是（）

A.颅内脑组织散在出血点

B.颅内小动脉痉挛，脑水肿

C.血钙低下

D.代谢性酸中毒

E.高血压