The geography teacher said to the students: "The Earth is an ellipsoid, but with a small flattening rate, and in general calculations, it is often approximated as a sphere. You know that the Earth's radius R is 6,371 kilometers, which is quite a large number. Now imagine you wrap a hoop around the equator of the Earth, and at the same time, wrap another hoop around a spherical, large watermelon. If I increase the length of each hoop by one meter, and distribute the extra length evenly, then there will be gaps between the hoops and the Earth’s surface as well as between the hoop and the watermelon. Question: Is the gap between the Earth and its hoop larger, or the gap between the watermelon and its hoop larger?"