Because they change over time
<span>I think the pKa for acetic acid is about 4.74. Therefore Acetic
acid/acetate buffer will work best at 4.74 +/- 1 pH unit and so the pH 8 is far
removed from that. Hence it would not buffer at that pH at all.</span>
Variation means difference in genetic makeup between individuals within a specie.
False, the angle is consistently the same, yet the placement of the Earth at this angle directed at the sun is what allows the Earth to have seasons (Spring, Summer, ...) So the answer is false.
During the research Ambulocetus would be the first to consistently stay in water and Set over time they developed feet arms and <span>hands used to swim.</span>
