A great number of students said they were forced to practise the piano. A. to questionB.

问题补充：

A great number of students said they were forced to practise the piano.

A. to question

B. to be questioned

C. questioned

D. questioning

答案：

A. to question

B. to be questioned

(答案→)C. questioned

D. questioning

解析：考查过去分词做定语。Students与question构成被动关系，故使用过去分词做定语修饰students。B项是不定式，表示将来。而本题并不表示将来。句意;很多被询问的学生都说他们是被迫学谈钢琴的。故C正确。