问题补充:
It is typical of students to stay up deep into the night for the final exam.
A. to read
B. having read
C. to have read
D. reading
答案:
A. to read
B. having read
C. to have read
(答案→)D. reading
解析:句意:学生为了期末考试熬夜读书到深夜是常有的事情。这里read和stay up是同时发生的事情,用现在分词做伴随状语,选D。