.---I’m going to the States for further study.
---How long you there?
A. had , stayed
B. did, stay
C. have, stayed
D. are, staying
网友回答
A. had , stayed
B. did, stay
C. have, stayed
(答案→)D. are, staying
解析：考查时态。“我要去美国继续深造了。”“你要在那里待多长时间？”A表示过去完成；B表示过去；C表示完成；D表示将来和进行。根据am going to可知，应该是将来的事情。故选D。