What do sound waves move or travel through

Sara goes on a slingshot ride in an amusement park. she is strapped into a spherical ball that has a radius 3*10^2 of centimeters. what is the volume of air in the spherical ball? use this formula: volume of a sphere=4/3pi,r^3 , where r is the sphere’s radius.

How does human environment effect the biosphere

Is there any species that went extinct in recent years due to natural causes (not caused by human interaction). if so, what caused it?