1. — Excuse me. Have you seen ______ Audi car here? I parked it just here this morning.
— Is it ______ black one? A young man has driven it away.
A. a; the B. the; a C. an; a D. an; the
2. If you want to see a doctor, you should fix a date with him ahead of time. That is a common __________ in the US.
A. sense B. practice C. regulation D. reality