讯号的用法和样例：
例句
-
课程包括：电力系统，90分；讯号处理，88分；系统控制，92分；电力能源系统，92分；固体电子学，88分；通讯，94分。
Curriculum included: Electric power systems, 90; Signal processing, 88; Systems and control, 92; Electric energy systems, 92; Solid-state electronics, 88; Communications, 94. -
变频器将无线电讯号从一种频率转换成另一种频率的电子装置
An electronic device that converts one frequency of a radio signal to another.
