Problem: - The animal eats large quantities of food that will be stored as fat - Winter comes and the animal finds a place to hibernate - Over a period of days, the animal's heart rate and breathing rate drop slowly - Electrical activity in the brain almost ceases completely, though some areas remain active What might be the last step of the process?

A: The animal has entered hibernation mode

Problem: - You breathe oxygen into your body through the nose or mouth - The oxygen travels to the lungs through the windpipe - The air sacs in the lungs send the oxygen into the blood stream - The carbon dioxide in the blood stream is transferred to the air sacs What might be the last step of the process?

A: The lungs expel through the nose or mouth back into the environment.

Problem: - Plants start growing on or near the rocks - The roots of the growing plants start to break up the rock - The plant acids dissolve the rock - The rock is broken down into smaller pieces What might be the last step of the process?

A: Erosion begins.

Problem: - Bats and other animals produce a high-pitched tone - The sound travels in waves, as sound does - The sound 'bounces' off of a nearby object - The sound wave returns to the bat - The bat hears the echoed sound - Folds in the bat's ear and adaptations in the bat's brain enable it to determine the size, shape, and position of the other object via the properties of the returned sound waves What might be the last step of the process?

A:
Other animals use echolocation in generally similar ways