自用的词频单词列表, 根据出现在 iweb，coca 语料库的频率选出。 top5000表示每个单词的某一词性的频率或者出现在口语中的频率是top5000
A list of self-used vocabulary frequency words, selected based on their frequency of occurrence in the iweb, coca corpus. top5000 means that each word has a certain lexical frequency or appears in the spoken language top5000