Try this: Take a photo and upload it to Facebook, then after a day or so, note what the URL link to the picture is and then delete it.
出自-2010年12月听力原文
In the case of Facebook, the company says data may hang around until the URL in question is reused, which is usually "after a short period of time", though obviously that time can vary considerably
出自-2010年12月听力原文
柯林斯高阶英汉双解学习词典释义
N-COUNT
统一资源定位器；网页地址；网址
A URL is an address that shows where a particular page can be found on the World Wide Web. URL is an abbreviation for (缩略=) 'Uniform Resource Locator'.