參考答案：
    1. B 2. D 3. A 4. C 5. B 6. A 7. C 8. D 9. A 10. D
    11. C 12. D 13. A 14. D 15. C 16. A 17. B 18. C 19. B 20. D
    21. C 22. D 23. A 24. B 25. A 26. C 27. D 28. B 29. A 30. B
    31. D 32. D 33. A 34. A 35. C 36. D 37. B 38. B 39. A 40. C
    41. B 42. D 43. A 44. C 45. C 46. A 47. B 48. D 49. A 50. B
    51. D 52. B 53. D 54. C 55. C 56. B 57. A 58. C 59. A 60. A
    61. C 62. D 63. A 64. B 65. C 66. A 67. B 68. D 69. C 70. D
    S1. whether or not one was a native speaker.
    S2. The same status as their counterparts.
    S3. Ones who can teach and have the required English level.
    S4. Non-native English teachers have been liberated. Or: It singled out the unqualified.
    S5. qualified English teachers because they were non-native speakers.