<span>bones and footprints preserved in stone are examples of fossils. Fossils hardened animal remains such as shells, bones, and teeth.</span> That is the best i can come up with. Hope it helps any.
As for this problem, the most probable answer and the most likely answer for this one would be D. the effect of pesticides on organisms in the environment.
A toxicologist would only study about chemicals and their effect on organisms in the environment. Pesticides are chemicals made to combat organisms that aren't wanted particular parts of the environment such as crops and rice field. These pesticides don't just affect those organisms that are targeted, but even the users and other organisms that may have come in contact with pesticides.
Answer:population can affect the level of oxygen in water because of the too much of oxygen being released
Explanation:
it can show us our history and may help us discover relatives we never new we had or lot contact with.