Determine the division of labor and order of all authors when submitting the manuscript for the first time, and don't change it at will in the future. It is very risky to modify the author's information when editing, and it may even be rejected. So it's best not to delete the cover letter.

The cover letter contains these contents: thank the editor for arranging the review and thank the reviewers for their valuable opinions. According to the requirements of the reviewers, the author answered the questions carefully one by one and carefully revised the article, all of which were focused. Thanks again to the editors and reviewers for their help.