单纯性二尖瓣狭窄的病变不伴有（）
A.左心房肥厚
B.左心房扩张
C.右心室肥厚
D.左心室肥厚
E.心脏呈梨形
参考答案：D
the final round in Shanghai September 30, the television show“The voice of China
raised one billion Yuan in advertisement bidding for its second season.
A．Having finished
B．To finish
C．Having been finished
D．Finishing
（______）（4a2-2ab+______）=-8a3-b3
