Answer:
Gas exchange between tissues and the blood is an essential function of the circulatory. The air contains oxygen that crosses the lung tissue, enters the bloodstream, and the alveoli are in direct contact with capillaries of the circulatory system. As water flows over the gills, oxygen is transferred to blood via the veins.
Explanation:
Answer:
1. A massive star depletes its nuclear fuel; gravity overpowers the star; supernova occurs; core of star collapses
2. black hole; gravitational pull
3. The center of the Milky Way
Explanation:
Answer:
The solid layer making up the surface of the Earth is the crust
Explanation:
The widespread, large scale, worlddwide burning of enormous quantities of fossil fuels for their energy, such as coal, oil, and natural gas, could do that, if it ever began and became popular.
Oh, wait ! That"s what we've been doing, for a couple of centuries now !
I’d say that it’s inventive