Why do they pressurize the cabin of airplane at 7,000 ft

Which of the following statements best explains the relationship between medicines and concerns about the shrinking of the amazon rainforest?

Which of the following statements does not describe the raccoon dog

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