I’m tired out．I stayed up the whole night, for my midterm math exam．
A. studying
B. to study
C. to be studying
D. studied
网友回答
(答案→)A. studying
B. to study
C. to be studying
D. studied
解析：考查非谓语动词.句意:我累坏了。我熬了一夜，为了我的数学其中考试学习。现在分词表示正在发生的，伴随性的动作。其逻辑主语为主句的主语，study的逻辑主语是I，故选A。