Ethiopification
金属沉着性皮肤黑变
🗣️ 情景例句
Don't lose your cool.
要沉住气。
May I speak to Mr. Johnson, please?
我想请约翰先生听电话好吗？
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。