Heat from the Sun causes water to evaporate from the surface of lakes and oceans. This turns the liquid water into water vapor in the atmosphere. Plants, too, help water get into the atmosphere through a process called transpiration!
Think of it like this. Horses do a LOT of galloping, which is hard on the feet! Hooves are a physical ADAPTATION, so that the horses won't experience pain on their journeys. They're hard, so that the horses don't feel the ground nearly as much. Now, mountain goats travel over rough terrain, with sharp rocks and steep inclines. Again, it's really easy for them to get hurt strutting around the mountains, so they evolved hard hooves to protect their feet.
I think the answer is Herbivores
You can check how fast your heart is beating.
