Given the fact that:  The higher the temperature, the more energy the particles have and the faster they will move and diffuse.  Answer the question:   As we move slower we wind up getting hotter or cooler?
cooler

Given the fact that:  The smaller a population is, the more allele frequencies may drift.  Answer the question:   A family that is very small, compared to one that is enormous, will have allele differences that are smaller or greater?
smaller

Given the fact that:  In erosion, a slower moving stream will only carry smaller particles.  Answer the question:   A slow stream is capable of moving boulders or sand?
sand

Given the fact that:  The larger the animal, the heavier the exoskeleton, making movement more difficult.  Answer the question:   Ease of mobility increase or decrease when the animal is decreased in size?
increase