—Miss Smith once music in Africa for eight years and now is an actress.
—No wonder I often hear her sing in the garden.
A. has taught B. was teaching C. taught D. had been teaching
98. I ______ the neighbour’s cat this week while she’s in hospital.
A. feed B. would feed C. am feeding D. was to feed
99. — Do you smoke?
— No, I don’t. But I used to. It’s 20 years since I ______.
A. didn’t smoke B. have smoked C. smoked D. began to smoke
答案全是C,为什么
参考资料:英语牛人团