Homeostasis is how the body functions to remain working perfectly. The body tries to maintain equilibrium and through all of the body's organs working together, homeostasis is achieved. For example, when you run your body exerts sweat. Sweating is your body maintaining homeostasis. Your body temperature is getting to high, so your body cools you off by releasing sweat. The answer in this case would be "a process by which organisms keep internal conditions relatively constant despite changes in external conditions"
While moving in between areas of land glaciers erode the land around them, this eroded land leads to weathering from the sand and rocks eroded. Example The Grand Canyon