21. I have joined ______ health club across the street to get in ______ shape.
A. the; 不填 B. a; 不填 C. the; the D. a; a
22. --- Was Tom at the party when you arrived?
--- Yes. But he ______ home soon afterwards.
A. goes B. would go C. had gone D. went
23. He suddenly had the feeling of ______. But when he looked around, there was nobody.
A. followed B. being followed
C. following D. having followed
