下列哪些是主动脉瓣关闭不全的病因()
A.风湿性心脏病
B.主动脉夹层动脉瘤
C.马方综合征
D.细菌性心内膜炎
E.先天性主动脉瓣畸形
参考答案:A, B, C, D, E
David talked with a friend of ____ on the Internet for a long time yesterday.
A.he
B.his
C.him
D.himself