请告诉我一张标准的A4纸的尺寸，要求回答必须是完整句子，不能出现数字和单位，使用简洁的英语陈述。

A standard A4 paper size is a commonly used full-sheet document format.
user
A standard A4 paper size is a widely recognized document format typically used for a variety of printing and writing purposes.
assistant