According to the different frequencies, the sound can be classified into ( ).
A: audio sound
B: ultrasonic wave
C: infrasonic wave
A: audio sound
B: ultrasonic wave
C: infrasonic wave
举一反三
- The sound wave is (). A: Mechanical transverse wave B: Mechanical longitudinal wave C: Electromagnetic wave D: X<br/>rays.
- The sound clicks differ from the squeals in that______. A: they are different in speeds of spreading B: they are different in wave length C: they are different in tones D: they are different in volumes
- ____: n. the rate at which a sound wave, light wave, or radio wave moves up and down 震动频率
- original sound wave A: 原来的声音 B: 原始音波 C: 声音信号
- A<br/>piezoelectric crystal is used to produce the ultrasound waves. What<br/>kind of ultrasound is produced? () A: Pressure<br/>wave ultrasound B: Electrical<br/>wave ultrasound C: Sound<br/>wave ultrasound D: Simple<br/>ultrasound