麻烦帮忙看一下这个英语句子 分析语法结构
It struck us that e-mail is still the main communication tool on the web,which seemed remarkable given that it is 20-year-old technology.
逗号后面的which seemed remarkable given that 这个是什么结构和用法,怎么翻译,希望给出语法结构上的分析不要简单的翻译