This involves selectively breeding two or more populations of a species or subspecies with desirable traits that are wanted by the humans. The offspring of the populations will bear the desired traits from the population. Breeding can be done over generations. An example is the breeding a cattle population that is resistant to drought and another that produces more milk. The filial generations will bear both traits.
The water molecule slows down, meaning that it freezes because When water vapor in the atmosphere cools down, it will condense and change back into liquid water, forming clouds.