____ by his teachers, he felt nervous.  [ ]    

A. Having watched      

B. Having been watching  

C. Watching  

D. Being watched

实现理性认识向实践的飞跃必须具备的条件是( )。

A．理论必须被群众所掌握，化为群众的自觉行动

B．要做到理论与实践相结合的原则

C．要把理论的正确性和现实的可行性结合起来

D．指导实践的理性认识应该尽可能地正确