A main ingredient to a well-made browser is its functionality. What can it do?  Almost all five browsers are equal when it comes to tabs, bookmarks, auto-completion of fields, but only { -brand-name-firefox } and { -brand-name-safari } offer add-ons/extensions, which are kind of like apps for your browser to make it more private, powerful or just more fun.
一款浏览器是否优秀，功能是关键。它能做什么？在标签页、书签、自动补全字段方面，五款浏览器几乎平起平坐，但只有 { -brand-name-firefox } 和 { -brand-name-safari } 支持附加组件/扩展——可看作浏览器上的应用程序，让它更隐私、更强大或更有趣。