69. It is such an expensive training course that I can't afford it
=> Câu này mình nghĩ đề có nhầm lẫn nha. Trên là thì hiện tại đơn mà dưới lại cho từ was nên mình sửa lại "is" ạ
70. I'd rather you didn't smoke in my house
=> S + would rather + somebody did something
72. But for Mike's being interested, the trip would have been cancelled
73. The pollution problems have been discussed by the students since last week
=> Bị động (Passive Voice)
