They were surrounded by the enemy, but they________at last from the village. [ ]

A. managed escaping  

B. tried to escape

C. managed to escape  

D. tried escaping

下列感受器的生理特性中，错误的是（）。

A．具有换能作用

B．仅对适宜刺激发生反应

C．对刺激可发生适应

D．感受器的敏感性可受中枢调制

E．受刺激后可产生发生器电位或感受器电位