his free time he often watches ball games TV.A. On inB. On onC. In inD. In on

问题补充：

his free time, he often watches ball games TV.

A. On, in

B. On, on

C. In, in

D. In, on

答案：

A. On, in

B. On, on

C. In, in

(答案→)D. In, on

解析：根据语境可知此句的含义是在空闲时间，他经常在电视上看球赛。此题考查的固定短语是 in one’s spare time表示在某人的空闲时间，固定短语on TV表示在电视上。故选D。