Mercury because it is way too hot to have an atmosphere.
Both are used for energy to the body.
A bottleneck is very narrow, which means that only a portion of the contents of the bottle cat get out (at the time).
From this effect, people use the word bottleneck when only a few individuals of a population survive:
the answer is: I<span>nsecticide spraying eliminates all but a few of the beetles on an island.</span>