—Have you been working in N0.5 Middle School since you graduated from college?~No I in t

问题补充：

—Have you been working in N0.5 Middle School since you graduated from college?

~No, I in the countryside for 3 years.

A. have taught

B. had taught

C. have been teaching

D. taught

答案：

A. have taught

B. had taught

C. have been teaching

(答案→)D. taught

解析：本题考查动词时态。由问句时态Have you been working可知说话时间是现在和现在在N0.5 Middle School工作；再由“No”可知“并非一直在N0.5 Middle School工作”， 结合这两者点可判断在此之前曾在农村工作了3年。所以选D。