------ You don’t look well. Are you ill?
------ No, the exam is ing, and I reading until midnight.
A. kept up
B. got up
C. stayed up
D. work up
网友回答
A. kept up
B. got up
(答案→)C. stayed up
D. work up
解析：考查动词短语：A. kept up维持，B. got up起来 C. stayed up熬夜D. work up逐渐造成，句意：--你看起来不好，生病了吗？--没有，快考试了，我熬夜看书到午夜。选C。