Which of the following is an example of sound refraction?
a).sound waves bouncing off a canyon wall to create an echo
b).reverberations in a concert hall
c).a high pitch sound changing to a low pitch sound
d).sound waves changing direction as they encounter different air temperatures

Melissa lives in a town called greendale. she discovers that when she lights a match and holds it near her kitchen faucet, the little flame grows into a larger fire. melissa is surprised because she thought the water would extinguish the flame rather than ignite it further. her mother tells her that the water might be contaminated with dissolved methane, a primary component in natural gas. melissa investigates the matter and finds that cases of methane contamination started shortly after a company began fracking for natural gas in the area. based on this information, which three statements are plausible consequences of fracking in greendale?

Study this image. which statements best describe the rock shown? check all that apply. the grains of this rock are jagged. this rock has several coarse grains. the grains in this rock are very large. this rock has a non-banded pattern. the color of this rock is determined by its texture.

What is the surface temperature of the ocean where hurricanes form? greater than 80 celsius approximately 27 celsius at least 76 celsius less than 10.5 celsius