How do you know if something is living or not?

What are two ways in which waves erode the land?

Guard cells control which event? the growth of plants capture of solar energy gas exchange in leaves water absorption in roots

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of