They are always ready helping.A. forB. of C. to D. in

问题补充：

They are always ready helping.

A. for

B. of

C. to

D. in

答案：

(答案→)A. for

B. of

C. to

D. in

解析：be ready to do sth ;be ready for sth/doing sth “准备做某事”