—How long in America?
—Two years. I came back last month.
A. have you studied
B. do you study
C. would you study
D. did you study
网友回答
A. have you studied
B. do you study
C. would you study
(答案→)D. did you study
解析：考查时态：句意：--你在美国学习多久了？--两年了，我上个月回来的。说明在美国学习的两年是过去的时间。选D。