前倾坐位时易于闻及的是()
A.二尖瓣狭窄的舒张期隆隆样杂音
B.二尖瓣关闭不全杂音
C.主动脉瓣关闭不全的叹气样杂音
D.三尖瓣关闭不全杂音
E.肺动脉瓣狭窄杂音
参考答案:C
The song is so beautiful. Never before such a wonderful one![ ]
A. I have heard
B. have I heard
C. I heard
D. did I hear
以10m/s的初速度从10m高的塔上抛出一颗石子,不计空气阻力,求石子落地时速度的大小.(取g=10m/s2)。