引起右心室后负荷增加的疾病是（）
A.主动脉瓣关闭不全
B.三尖瓣关闭不全
C.房间隔缺损
D.阻塞性肺气肿
E.动静脉瘘
参考答案：D
颈淋巴清扫术后常用的引流方式为
A．片状引流 B．纱条引流 C．管状引流 D．负压引流
—______ did you sleep last night?
—Only five hours. I stayed up late to do my homework. [ ]
A. How soon
B. How often
C. How long
D. How much
