My guess would have to be hydropower, since water isn't an un natural substance
Answer:
C) male-male competition; sexual conflict and antagonistic coevolution
Explanation:
Male-male competition happens when two males of a species fight for the opportunity to mate with a specific female.
I believe true because the Precambrian is the first geologic time, going back 4600-570 years ago, meaning it should contain the earliest of things.
D because they are complete systems
Thyroid gland produces:
1) T3<span> (</span>triiodothyronine<span>)
2) </span>T4<span> (</span>thyroxine<span>).
3) T</span>hyroid stimulating hormone<span> (</span>TSH<span>)
Hope this helps!</span>
