Definition of gravity

the force that attracts a body toward the center of the earth, or toward any other physical body having mass.

Explanation:

the force that pulls us back to earth when anything goes up

so it pretty much means

whatever goes up always comes down

Explanation:

answer

fusion: the energy source of stars. the energy released from the collapse of the gas into a protostar causes the center of the protostar to become extremely hot. when the core is hot enough, nuclear fusion commences. fusion is the process where two hydrogen atoms combine to form a helium atom, releasing energy.

hope it