He found very interesting a horse.A. that; to rideB. it; ridingC. it; to ride D. it is;

网友回答

A. that; to ride
B. it; riding
(答案→)C. it; to ride
D. it is; to ride
解析：that一般引导从句，it一般用作形式宾语或者形式主语。本句不是宾语从句，it指代下文不定式内容做形式宾语，故选C。