Double-checking is not about your program code, but about the content of the paper. Generally, we use HowNet to check the duplicate. Generally, check whether a sentence or a paragraph in your paper has similar fragments in the database. If it is very similar or exactly the same, it is a point of repetition. Check the whole paper before reading your repetition. If it is too high, you will be asked to revise it and check it again. You can check it on Taobao before the school sends it for inspection. There are a lot of duplicate checks on Taobao, but HowNet is more expensive (I remember it was more than 100). You can use others, just a few dollars. If you find a high repetition rate in other websites, then you can modify it, and the modification is also skillful. You can look it up online (for example, if a sentence is repetitive, you can not repeat it if the sentence order is disrupted. Generally, if you search on Taobao, he will also send you some modification skills. Change it to, your repetition rate is only below 10%, which is basically the same.