| http://www.w3.org/ns/prov#value | - Without them the sun's energy would not reach the earth, and power photosynthesis, the water cycle, and keep us from freezing solid.Another kind of wave is sound waves. (Many of the principles that apply to electromagnetic waves also apply to sound and other mechanical waves, but there are significant differences.) Without sound, I could not hear voices or music or various kinds of signals and warn
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