答案:Exercise 1
1. B 2. D 3. C 4. B 5. D 6. B 7. A 8. D 9. C 10. D
Exercise 2
1. D (改为:have used)
2. B (改为:didn't dare)
3.D (删去:being)
4. C (改为:be having)
5. B (改为:have liked)