Which statement best explains why earth is not a perfect sphere?
earth revolves too quickly around the sun
earth's spin on its axis causes the equator to bulge
the circumference of the earth is greater at its poles
the gravity of the moon changes earth's shape

Earth's spin on its axis causes the equator to bulge

Explanation:

The Earth is not a perfect sphere but an oblate ellipsoid. The force that holds a planet is gravity. The Earth is rotating on its axis at a speed of 460 m/s at the equator. Due to this reason there is a build up of centrifugal force on the Earth which causes it to expand giving it a bulge.

The Sun and the Moon's gravity causes waves on the surface of large water bodies.

for this one it would be d bump/forearm pass

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .