Infer: Farmers add nitrogen to their fields every year to help their crops grow. Why must farmers continually add nitrogen when this element recycles naturally?

c. establishing proper sleep hygiene

imagine a line passing through the center of earth that goes through both the north pole and the south pole. this imaginary line is called an axis. earth spins around its axis, just as a top spins around its spindle. this spinning movement is called earth's rotation. at the same time that the earth spins on its axis, it also orbits, or revolves around the sun. this movement is called revolution.

c.           is the correct answer