Respuesta :
Answer: The correct word for the blank is 'oscillates'
" a mechanical wave is created when a medium oscillates , or moves back and forth or up and down
Explanation:
When the matter oscillates or vibrates it transfers energy through the medium in the form of wave which termed s mechanical wave.For example: Sound wave,slinky waves, water waves are the examples of mechanical waves.
So, " a mechanical wave is created when a medium oscillates , or moves back and forth or up and down