look at the figure above. which atmosphere layer has around 80 percent of the mass of the earths atmosphere?

the earth is thought to have been formed about 4.6 billion years ago by collisions from a cloud of hydrogen, helium, rock, ice and other materials. these were pulled together by gravity to form objects in and around earth like- asteroids and small early planets called planetesimals.

so, the best possible answer to this question will be option d- to harden materials to form different parts of earth’s layers

answer; coat color for blending in with dry grass;

answer; the male's sperm cells have mitochondria, but because the sperm contributes dna but no cytoplasm, no mitochondria are passed to the egg at ferilization;