Austin-Flint杂音的发生与以下哪项有关
A．二尖瓣狭窄B．二尖瓣关闭不全C．主动脉狭窄D．主动脉关闭不全E．肺动脉关闭不全
参考答案：D
(2013·台州高三检测)Linda’s health is improving________day by day，and the doctor has advised her to stay home for a couple of weeks.
A．frequently
B．gradually
C．fluently
D．actually
简述制订压下规程的步骤？
