21. Why did the author＇s father think of her as a problem?

54. What does the author suggest scientists do about public debate?

53. Why does the author say some experts＇ anxiety seems misplaced?

52. Why did a recent debate published in The New York Times arouse concerns among experts?

51. What does the author think open debate can do?

50. What does the author think constitutes a key part of genuine education?

49. What problem may arise if classes go online?

48. What does the author say is one disadvantage of online classes?

47. What does the author think of online course assignments?

46. What does the author say about students enrolled in online classes?

55. Why couldn＇t technology replace a good teacher?