Ten minutes had been made full of the problem.
A. using; studying
B. use; to study
C. to use; to study
D. use; studying
网友回答
A. using; studying
(答案→)B. use; to study
C. to use; to study
D. use; studying
解析：句意：十分钟的时间正在被充分利用来研究这个问题。make full use of 充分利用，用的是被动语态，目的是为了研究这个问题，to表示了为了什么目的
选B。