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Which of the following terms describes the layers of air surrounding the earth ?

Which revelation resulted from the observation of the spectrum of different galaxies? a. there were more galaxies whose spectrum was blueshifted b. there were no galaxies whose spectrum was redshifted c. there were more galaxies whose spectrum was redshifted d. there were no galaxies whose spectrum was blueshifted

All of the following are reasons why deserts extremely susceptible to wind erosion except a. they lack major root systems b. they contain thin, dry soil c. they have very few plants and trees d. they are extremely hot and lack water