13. B. not writing
=> not to write
14. C. for working
=> be unwilling to do sth
15. B. being
=> to be
16. A. swimming
=> teach sb to do sth
17. C. that we got
18. B. for making
=> encourage sb to do sth
19. A. to drive
=> let sb do sth
20. B. came
21. B. that follow
22. B. to go into
23. B. of allowing
24. C. meeting me
25. B. for staying out
26. C. used to doing
=> used to do: được dùng để ...
