(1)指定一篇英文文章（文本文件的形式），统计该文章中的所有单词的出现次数；

(2)按照单词出现的次数由大到小进行排列；

(3)能够把统计结果保存到某个指定的文件。-(1) specify an English article (text file), statistics for all words in the article occurrences

(2) in accordance with the number of times the word appears descending arranged

(3) the statistical results can be saved to a specified file.