His spare time is made full use law.
A. to study
B. study
C. of studying
D. of to study
网友回答
A. to study
B. study
C. of studying
(答案→)D. of to study
解析：考查固定短语和不定式表目的。make full use of sth充分利用，句意：他的空闲时间被充分利用来学习法律。原句可改为：He made full use of his spare time to study law.动词不定式表示目的，故选D。