— Why, David, you look so tired!
— Well, I an article and I must finish it tomorrow.
A. was writing
B. will be writing
C. have been writing
D. have written
网友回答
A. was writing
B. will be writing
(答案→)C. have been writing
D. have written
解析：考查时态，句意：大卫，你为什么看起来这么累呢？哦，我一直在写文章我必须明天完成。根据语境动作是从过去开始一直持续到现在还要持续下去，故用现在完成进行时，选C。