recurrent code

例句：

1. 1. The disease is recurrent in this area.
   这种疾病在这个地区是反复出现的。
2. 2. The teacher often gave the same lectures, which made the students feel recurrently bored.
   老师经常讲同样的内容，这让学生们感到反复地无聊。
3. 3.The recurrent problem of overwork has become a major concern for many companies.
   不断加班的问题已经成为许多公司的主要担忧。