Pharynx and for those who didn't know its the very back of your mouth)
I believe the situation is something like the birds with shorter/longer beaks (depending on the situation) survive.
To answer the question, we have to understand the meaning of natural selection. natural selection is where the organisms with more favourable characteristics survive and reproduce and pass on the genes to offsprings while some of the organisms with less favourable characteristics die, so that there would be more organisms with that favorable characteristic in the population.
So in order to have natural selection happen, Birds must have different lengths of beaks, in order to make it happen, genetic variation must occur. if all the birds have the same length of beak, the either all survive or die, which is not the definition of natural selection.
Therefore, your answer should be genetic variation.
Since Precipitation is rain evaporation is water which is turning in to gas and goes to the air or atmosphere
<span>When the terminal (third) phosphate is cut loose, ATP becomes ADP (Adenosine diphosphate; di= two), and the stored energy is released for some biological process to utilize. The input of additional energy (plus a phosphate group) "recharges" ADP into ATP (as in my analogy the spent batteries are recharged by the input of additional energy).</span>
This property of water affects life on Earth because it<span> floats on the surface, sustaining life at the bottom of lakes and oceans</span>