1. C keen ( be keen on + N/Ving: thích )
2. B get over
3. A old enough ( adj + enough )
4. A have done ( this is the first time + S + have/has + Vpp )
5. C Thank you
6. A It's nice of you to say so
7. C if she was planning
8. D could speak
9. C would buy
10. D more carefully
11. C to read
12. C keep in touch
13. B knew
14. A to protect
15. C am used to
16. C designers
17. B are sold
18. D examiner
19. B. exploring
20. D doesn’t she
21. B turning
22. B traveling/ standing
23. C to work
24. C mountainous
25. D has practised