The questions in the process of writing a paper are repeated according to your paper. If 13 similar words appear continuously, they can be judged as duplicates. In this way, students' systematic design will mark the repeated sentences with red flags. By comparing duplicate checking reports, the author can know the reason of high repetition rate in time. There are many commonly used duplicate checking tools, which can check the repetition rate and meet the requirements of schools, which is one reason why many universities like to use them.