The law of over－learning explains why cramming (突击学习) for an examination, though it may result in a passing grade, is not a ________ way to learn a school course.[ ]

A. convenient  

B. demanding

C. satisfactory

D. swift

宋代理学三种“本体论”学派不包括（）。

A、以气为主

B、以理为主

C、以心为主

D、以道为主