First of all, since it is a quotation, don't add your own opinions. Some papers have false quotations, and the quotation format is very incorrect, which will lead to errors in the content of the papers and high duplicate checking rate. We can't just write the quoted content just to prove our point of view, and we can't make a little or more changes to the original content sentence when quoting, but also add most of our own points of view to the quoted part. That's not a quote.

Secondly, you can't distort the quoted content. The content we quoted must be original, without many changes and distortions. In fact, many people will use an argument, which is also very understandable, but we should do it according to the original work, do not distort the original point of view, and also be able to restore the original appearance.

Finally, it is not advisable to add and subtract at will. If the cited literature thinks there are many contents, it can be deleted at will. Also, if they think there are few contents and their opinions are insufficient, they can't modify, add or delete most of them at will, and then quote some of them as references. No matter what our purpose is, we need to be consistent with the original meaning, and we can't take it out of context. It is impossible to distort the original intention. First of all, we should understand the main idea of the whole paper. We can't just choose a few sentences to use, and we don't know the meaning. Then it will lead to violation of the original intention and the quotation is not in line with academic ethics.