> For the complete documentation index, see [llms.txt](https://www.oulan.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.oulan.com/2016/11/10.md).

# 10

你只有一双脚，不能同时跳两场舞。

![](/files/-MCbZVaGVDU7IysZ5Vsk)