洋地黄类药物的常见心血管系统毒性反应为各种心律失常，最常见的是
A．窦性心动过缓
B．房室传导阻滞
C．室早二联律
D．房颤
E．室性心动过速
参考答案：C
简述水肿的发病机制。
A narrative description of products or services to be supplied under contract is called______.
A．the project plan
B．a statement of work
C．an exception report
D．a Pareto analysis
