Anyway Jack knows help about travelling .A. who to askB. who to ask toC. who to ask forD

问题补充：

Anyway, Jack knows help about travelling .

A. who to ask

B. who to ask to

C. who to ask for

D. to ask for who

答案：

A. who to ask

B. who to ask to

(答案→)C. who to ask for

D. to ask for who

解析：句意：不管怎样，杰克知道向谁求助旅行知识。ask for help求救，疑问词加不定式做宾语，故选C.