Here's why:

* Contour lines represent points of equal elevation on a map.

* Closely spaced contour lines mean the elevation changes rapidly over a short distance, resulting in a steep slope.

* Widely spaced contour lines mean the elevation changes gradually over a longer distance, resulting in a gentle slope.

Think of it like this: imagine you're walking uphill. If you encounter a steep climb, you'll notice elevation changes quickly. On a map, this would be represented by contour lines close together. Conversely, if the climb is gradual, the elevation changes slowly, and the contour lines would be spaced farther apart.