Very grateful for any help with these three clues please.
7ac: "Work at the centre of constabulary' case? (4)." I have C-P-.
13ac: "Some exercise? It ain't so bad, son (4-3)." I have C-I-,U-S.
21ac: "Dug-out tunnels reviewed by a prisoner here? (6)." I have --A-A-.