The inside surface is resistant to water, so the coat can be          when it rains.[ ]

A. deserved

B. reversed

C. reserved

D. preserved

强心苷治疗心房纤颤的药理学基础是（ ）

A．加强心肌收缩力

B．降低窦房结自律性

C．减慢房室传导

D．缩短心房有效不应期

E．降低浦氏纤维自律性