With any social network, adding a contact doesn't necessarily open an otherwise closed communications channel with that person; it merely invites such openings.
对于任何社交网络，“添加好友”并不一定意味着和别人建立尚未开通的交流渠道，它只是提供了一种可能性。
2
The channel resistance includes the resistance of the closed contact, the printed circuit traces, and the output connectors.
通道电阻包括闭合触点的电阻、印制板走线和输出连接器的电阻。
3
The measurement is made with one channel open and one channelclosed.