trumpet the sound from the trumpet comes from a vibrating column of air created by buzzing lips of the trumpeter A sound wave is a longitudinal ... earlier in this topic human beings can generally ...
What questions do you have about the human body ... times heavier than air. So sound waves move slower through it, which amplifies the lower frequencies in your voice. But here's the fascinating ...
一些您可能无法访问的结果已被隐去。
显示无法访问的结果