21. If there is _____ emergency, they have to travel three hours to get to ____ nearest hospital for help.
A. the; / B. an; the C. /; the D. an; a
22. The idea of cloning extinct dinosaurs _____ a mixture of fear and excitement into people’s hearts, as evidenced by the popularity of Jurassic Park.
A. knocked B. hit C. struck D. beat
23. She brought with her three friends, none of _____ I had ever met before.
A. them B. which C. whom D. who
24. _____is compulsory by law for a citizen to undertake military service.
A. That B. There C. This D. It
