Backchannel
（传递消息的）秘密渠道, 特殊途径
🗣️ 情景例句
Are you being waited on?
您需要服务吗？
No. You're going the wrong way. You want the Number 11. It stops in front of the post office.
不去。你乘错车了。你要乘11路。它在邮局门前停站。
Yes, thanks. How's Kate?
很好，谢谢。凯特好吗？