21. The criminal, as well as some ______ people, was arrested by the police yesterday.
A. relevant B. skilled C. released D. lucky
22. Do you remember the chicken farm _____ we visited three months ago?
A. where B. when C. that D. what
23. I ______ my university professor in the supermarket near my house, which was out of my expectation.
A. came out B. came across C. came about D. came along