It was ______ great shock to the world that two airplanes crashed into ______ World Trade Centre in New York on Sept. 11.

A．a; ／

B．the；the

C．a；the

D．/；the

主动脉瓣关闭不全
扩张型心肌病

 A.主动脉型心

B.二尖瓣型心

C.双侧心界扩大

D.心绝对浊音界扩大

E.心底浊音区扩大