according to criteria such as salinity, depth, and whether the water is flowing or standing
<span>a cell that bears receptors for a hormone, drug, or other signaling molecule, or is the focus of contact by a virus, phagocyte, nerve fiber, etc.</span>
Answer:
1/ Climate change
2/ Asteroid impacts
3/ Massive volcanic eruptions
4/ Sun explodes
etc. (all the things above are most likely to happen but alien invasion or things like that is also a theory that you can add depends mostly if you like it or not)
