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1·Therefore, the upward and downward of the communication indicates its effective functionality in a lateral direction.

因此，通信的向上和向下表示其在横向方向上的有效功能。

2·Communication flows according to the formal chain of command, both upward and downward.

沟通信息按照正式的指挥链流动，既可以上行，也可以下行。

3·The direction of communication can be upward, downward or horizontal.

沟通的方向可分为下行沟通、上行沟通和平行沟通三大流向。

4·Since the downward conversion photon pairs have strong correlation in time, they can be used for noise - free optical communication.

由于下转换光子对具有很强的时间相关性，可用来进行无噪声的光通讯。