🗣️ 情景例句
He was my roommate in college.
他是我大学时的室友。
He answered almost all of my questions.
他回答了我几乎所有的问题。
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。