Answers

The Brainliest Answer!
2016-03-13T18:07:15+05:30
When particles come together , they form a compression.When they move away, they form Rare fraction.
Compressions are regions of high density and high pressure.Rarefactions are regions of low density and low pressure.
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2016-03-13T18:07:39+05:30
compression is the region of high pressure or high density
while,
rarefaction is the region of low pressure and low density 

i hope it helps........ 
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