It is recommended to write papers in Docx format, because it is the default document format of Microsoft Office 2007 and later, and has the following advantages:

1. Better compatibility: docx format is more stable than doc, and it can be opened and edited on different platforms, so it is more compatible across versions.

2. More format options: docx format can better preserve the format and style of documents, such as page settings, headers and footers, styles, numbers, directories and so on.

3. Better support for pictures: docx format supports more picture file formats, which can better handle media materials such as pictures.

In a word, the efficiency and quality of writing and editing can be better guaranteed by using docx format. However, please note that before submitting a paper, you must check the requirements of the journal or school and submit it in its specified format.