问题补充：
What the teacher said in class set all the a lot.
A. present students to think
B. students present thinking
C. present students thinking
D. students present to think
答案：
A. present students to think
(答案→)B. students present thinking
C. present students thinking
D. students present to think
解析：考查set的用法。Set+宾语+宾补（形容词、介词或v.-ing），意为“使处于某种状态”。句意“老师在班里说的话让所有在场的学生思考良久。”present“出席的，在场的”，作后置定语。故选B。
