Free
Think about your earliest memories of your neighborhood. Maybe new buildings have been built since then, or even new streets.
But, for the most part, your neighborhood is probably much the same now as it was then. If there are hills nearby, they’ve probably been there your whole life. If you live near a river or lake, it’s probably always been there, too. With all this sameness, you might think that Earth doesn’t change much. But the truth is, Earth is always changing.