H-12：have a hand in 参与

A：Are you having a hand in looking into the case?

A:你参与调查那件案子了吗?

B:Yes.

B:是的。

A:How do you feel about it?

A:怎么样?

B:It's really a hard nut to crack, The probelm is that the crime was done without leaving any trace.

B：案子很棘手，问题是犯罪分子未留下任何线索。