在线投稿时的Cover Letter 应该怎么写

1)
若不额外上传 cover letter,
则可能是 Enter comments to journal office (or editor)
若是, 可以不写,也可以写~
2)
写的话, 格式没有要求, 通常分为 3 部分.
A. 先作者简短自介约一两句,
B. 然后简要描述前期的研究工作,或是前人的工作概况,
C. 接着介绍本文的主要工作,与前人工作不同之处, 及主要的贡献(热点)

以下为参考：
Dear Editor,
We would like to submit the enclosed manuscript entitled "Effects of integrated agronomic management practices on yield and nitrogen efficiency of summer maize in North China", which we wish to be considered for publication in Field Crops Research.
Agricultural nitrogen efficiency as well as grain yield has long been thought to be essential for cereal crops production. In this study, we report an optimized agronomic practice integrated cropping system and fertilizer management. Our results succeed for the first time in achieving synchrony of high grain yield and high nitrogen (N) efficiency of summer maize (ZD958) in the winter wheat-summer maize rotation system in North China Plain. This manuscript has not been published elsewhere and the English has been professionally checked.
Thank you very much for your considering our manuscript for potential publication. I'm looking forward to hearing from you soon.

Sincerely yours,
name等信息