高等教育 / 大学英语（四）
The two scholars worked at the task of writing a preface to the new dictionary for three hours _ _ _ _ last night.
(A) at length
(B) in full
(C) on end
(D) in time
(A) at length
(B) in full
(C) on end
(D) in time
参考答案：
佳题速递：