Answer:
Oxygen is reduced, gaining electrons and hydrogen ions. -second choice
Trace fossil because a trace fossil is a fossil of a footprint, trail, burrow, or other trace of an animal rather than of the animal itself.
So by looking at the seismic waves from earthquakes the scientist learned about the crust and the mantle but they also learned about the outer and inner core. To do this you have to look at a different kind of waves, the S (secondary waves) waves that also get released by an earthquake.
<span>Diffusion and osmosis are important to cells because they don't require energy to transport very important molecules such as water and steroids.</span>
The deeper down you get, the colder the water is