肺动脉瓣区第二音亢进和固定分裂多见于
A．房间隔缺损
B．室间隔缺损
C．动脉导管未闭
D．法洛四联症
E．肺动脉瓣狭窄
参考答案：A
—Would you like another cake,please?
—_____. I'm full now. [ ]
A. No, I don t want
B. No, thanks
C. Yes, please
中等水平回声见于（）
A.肝实质
B.骨骼
C.胆结石
D.肌腱
E.血管壁
