The librarians have compiled a card-index catalogue so that they can afford facilities for reference.

为便于参考起见，图书馆馆员们编制了索引目录卡。

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But users need a "tracker" link to find what they're looking for - like the index card in a library catalogue.

但是用户需要tracker服务器来连接他们所要寻找的文件，就像图书馆目录中的索引卡。

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