胸骨左缘第3~4肋间收缩期震颇见于
A.主动脉瓣狭窄B.肺动脉瓣狭窄C.室间隔缺损D.二尖瓣狭窄E.动脉导管未闭
参考答案:C
____ is the ninth month of a year. [ ]
A. September
B. August
C. October
压力容器操作人员应按照有关规定经专业机构培训,并应取得相应的从业资格。