O is what should go in the blank. O stands for Oxygen.
Yes that’s correct it is B
B) land cools off much faster than water (creating a air region of high density above land and lower density above sea)
Should be their masses. Because t<span>he strength of the gravitational force between two objects depends on two factors, mass and </span>distance<span>. the force of gravity the masses exert on each other. If one of the masses is doubled, the force of gravity between the objects is doubled. increases, the force of gravity decreases.</span>