Why isn’t the man going to work
[A] The boss wants him to have a rest.
[B] He wants to go for a picnic.
[C] He is sick and has to stay home.

血管扩张药治疗心衰的主要药理依据是（）

A.扩张冠脉，增加心肌供氧

B.减少心肌耗氧

C.降低心排出量

D.降低血压，反射性兴奋交感神经

E.扩张动、静脉，减轻心脏的前、后负荷