在真实世界里，对一个联系人来说“最近修改时间”可能没有什么真正的意义，而只是一个模型在系统中怎样被使用、跟踪、持久化的功能而已。

The modified date has no real meaning for a contact in the real world, but is a function of how the model is used, tracked, and persisted in the system.

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比如，一个联系人记录可能包含一个“最近修改时间”和一个“修改用户的标识”，和一个“唯一标识”(数据库或持久化信息)。

For example, a contact record may contain a last modified date and the identity of the modifying user (auditing information), and a unique identifier (database or persistence information).

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人际网是让别人知道你最近在忙些什么，然后试探性的交谈得到新的联系人，以能够达到你的目的。

Networking is letting people know what you are up to these days and how you are putting out feelers to make new contacts so you can carry out your objective.

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