When choosing a duplicate checking system, we should choose a proper regular duplicate checking system according to the specific situation. If the first draft of the paper is drawn up, it is suggested that free duplicate checking software such as paperfree and papertime can be used for testing. The first duplicate check is free, and you can also get the number of words for online duplicate check by participating in the free duplicate check activity in official website. At the same time, it is suggested that the duplicate checking system should be used for detection, and comprehensive judgment should be made in combination with other duplicate checking results to ensure that the paper meets academic requirements.