19. A
20. C
21. B
22. C
23. B
24. A
25. D
26. D => was ringing -> rang
27. C => open -> opened
28. B => told -> asked
29. B => interesting > interested
30. D => so as to not -> so as not to
Nếu thấy bài giải hay + hữu ích, xin 5* + hay nhất ạ !
Học tốt !
#gkhanh