Which is the main function of the respiratory system? 1. to protect the internal organs
2. to help oxygen get into blood vessels
3. to push blood to all parts of the body
4. to protect the body from illness

Which mantle is under the crust the upper mantle or the lower mantle i think it's upper let me know if i'm right

How many major plates cover the earth

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