ultrasonic frequency range

• 超声频段

ultrasonic frequency range的用法和样例：

例句

1. Each channel remains at an assigned frequency within a single band.
   每个信道在单一的频段内保持分配的频率。
2. We can't hear any program when we turn our radio onto this frequency band.
   当收音机调到这个频段上时，什么节目也收听不到。