use the theory of natural selection to explain how the average running speed of population of zebras I increase over time

What is the question? if you were looking to design a method of separating something, you can separate this compound by putting both in water and allowing the water to dissolve the sugar. then pour it into another beaker and evaporate it then boom! salt and sugar : ) 

Dont understand the question

The rate that would change would be the  searching efficiency/attack rate. there are only two other rates in this model: the  growth rate of prey, and the  predator or consumer mortality rate.the  searching efficiency/attack rate is what indicates how effectively can a predator capture its prey whether in the searching process or actual capturing/attacking process. 

Your answer is water because there is combined mass of water found on, under, and over the surface of a planet. your answer is water.