«Please ignore the other answers, as they are simply ignorant and mindless sheep. They believe everything that their false government and schools tell them to believe.
To answer your question, the Earth is the ONLY planet that exhibits gravity because it is the only planet with humans inhabiting it. Thus, it is considered important enough by the universe to have gravity. As a result, the sun, moon, even the satellites, orbit us on the earth. Put more simply, the earth does not actually exhibit any gravity. We humans do. Underrated is the strength and resolve of the human mind.
P.S. If you would like to learn about more of the mathematics behind this phenomenon, make sure to visit spamlinkprobably»