The more actively involved in learning one gets, the more rapidly he/she will progress, that is, ________ plays an important role in knowledge acquisition.

1. A.
   courage
2. B.
   ambition
3. C.
   motivation
4. D.
   talent

The more actively involved in learning one gets, the more rapidly he/she will progress, that is, ________   plays an important role in knowledge acquisition.

A．courage    B．ambition    C．motivation D．talent