【问】1. There is a period____the end of this sentence.
 A. with B. at C. in D. on(TOEFL)
 2. She looked everywhere for her book but____had to return home without it.
 A. at the end B. in the end
 C. in the finish D. at the last(大学生英语赛题)
 为什么在句(1)中必须选at，而在句(2)中必须选in the end?
 【答】 in the end是指“最后”、最终”、“终于”(finally; eventually; the final outcome was that)，
 后面不跟of短语，常常独立地用作状语：
 1. I hope that everything will turn out all right in the end.
 我希望一切最终都很顺利。
 2. In the end they crossed the mountains and reached the Oregon Valleys.
 最后他们翻过了群山，来到了俄勒冈谷地。
 3. In the end they made some unimportant changes and they allowed him to print it.
 最后，他们作了一些不太重要的修改，就允许他把它拿去印刷了。
 4. Perhaps we shall find another form of energy in the end，but it will take a long time.
 或许最后我们会找到另一种形式的能量，但这需要很长时间。
 at the end后面常常跟着of短语，表示“在……末尾”、“在……尽头”：
 1. You will find an index at the end of this book.
 书后有索引备查。
 2. She was at the end of her patience.
 她已忍无可忍了。
 3. The process of mechanization has been developing and becoming more complex eversince the beginnng of the Industrial Revolution at the end of the 18th century.
 从18世纪末工业革命开始以来，机械化过程一直在发展，并变得越来越复杂。
 4. At the end of the last ice age，the Earth's climate began to change. (TOEFL)
 在最后冰川末期，地球的气候开始变化。
 如果在at the end之后不出现of短语，则从上下文可以看出是指“……的末尾”：
 I think the film's a bit weak at the end. (BEU)
 我认为这部电影的结尾差一点。
 (参见 at the beginning)