下列哪种疾病可在胸骨左缘第3~4肋间触及收缩期震颤()
A.肺动脉瓣狭窄
B.二尖瓣狭窄
C.主动脉瓣狭窄
D.室间隔缺损
E.动脉导管未闭
参考答案:D
两相邻界址点间,坐标反算距离与实地丈量距离的较差,不得大于______cm。
A.2 B.5C.10 D.15
He plans ____ a very relaxing vacation. [ ]
A. to have
B. having
C. to having