Tailwater
下游
🗣️ 情景例句
Typing is easy once you get the hang of it.
一旦你掌握诀窍，打字就很简单。
Thank you for you cooperation.
谢谢你们的合作。
This depends on the precise radio frequency of the 21-cm wavelength, or 1420 megacycles per second.
这种通讯联系要靠21厘米波段，即每秒1420兆周的精确无线电频率。