Fast-moving cold fronts force the warm air ahead of them to rise more quickly than slow movers. The clouds and rain are mostly along the front or ahead of it, and heavy rain or thunderstorms are common. A slow-moving front lifts the warm air more gradually; the rain is less intense, and the clouds form along and *behind* the surface cold front.
<span>If Noam chooses a filter, it might be more effective than a screen. After using it for a while, though, he will have to replace it, which could be expensive. A screen might be less effective, but it can be cleaned instead of replaced.</span>
<span>When an athlete is nearing the end of a race and her cells are low on oxygen, it is likely to be fermentation. When cells have used up all their oxygen they ferment glucose into lactic acid. Fermentation is a metabolic process that consumes sugar in the absence of oxygen</span>
Answer:
directional selection, is a mode of negative natural selection in which an extreme phenotype is favored over other phenotypes, causing the allele frequency to shift over time in the direction of that phenotype.
