How to quickly download an earlier version of Firefox

Today, at the sixth day of the new year, I started FF and found that it was automatically updated to version 27. I want to use it from version 3.5. Now, after so many years, okay, just run the question...

The updated ff often gets stuck during usage, but it hasn't been used before. So I 'd like to find the old version of ff to install it. I found that all the products provided by Du Niang are non-official products, so I came to the official website:

Http://www.mozilla.org/en-US/firefox/all/ opened to find no historical version of the download, hover the mouse over the line of Simplified Chinese, 1 shows:

The status bar in the lower right corner shows a URL, as shown in figure 2:

I can't see the version number. If I copy the URL and modify the version number, what will happen? For example:

Https://download.mozilla.org /? Product = firefox-17.0 & OS = linux & lang = zh-CN

Congratulations, you have downloaded the FF browser on the linux platform of Version 17.

Let's take full advantage of the rest.