Answer:
Gravitational force
Explanation:
Gravitational force is obviously one of the biggest obstacles in climbing. You are essentially going against this very strong force to pull your body mass up the beautiful terrain. Gravity is defined as the force of attraction between all masses in the universe, gravity is what allows the sport of climbing.
<span>1. It must be an object which independently orbits the Sun (this means moons can't be considered planets, since they orbit planets)
2. It must have enough mass that its own gravity pulls it into a spheroidal shape.
3. </span><span>It must be large enough to "dominate" its orbit (i.e. its mass must be much larger than anything else which crosses its orbit).</span>