This trick can also be immensely effective when you include lots and lots of smaller images from several servers (like gravatars for example) as these are not likely to be cached.

这种方法还适用于你需要从多个服务器取得许多不能被缓存的图片。

youdao

Users want gravatars, chat history, domain-level chatrooms, and notifications, among other goodies.

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