如果您在页面中引用基于Web的资源，   Expression Web将获取它以便它可以显示您的页面。如果那是"某事"需要花费很长时间才能获取，EW需要很长时间才能打开您的网页。

If you are referencing a web-based resource in your page, Expression Web will go fetch it so it can display your page. If that "something" takes a long time to fetch, it will take a long time for EW to open your page.

在您编辑网页时注释掉***代码并查看是否有所作为。

Comment out the *** code while you are editing your page and see if that makes a difference.

顺便说一句，"表达式设计"不是"Expression Web"。  Expression Web有一个论坛。

By the way, "Expression Design" isn't "Expression Web".  There is a forum for Expression Web.