What was the result of collisons between the early earth and other smaller protoplanets

What is the importantence of the carbon and nitretan cycles in the environment

Which would best keep the oxygen cycle stable? a. cutting down jungles to create farmland b. eliminating parks in large cities c. dumping toxic chemicals into the ocean d. reducing the amount of deforestation d. reducing the amount of deforestation

Compare the composition of the moon's surface with the composition of the earth's surface.