Answer:
The answer is B.
Explanation:
The United States has been progressively expanding towards the southwest since the start of the country.
Surface runoff is a term used to describe when soil is infiltrated to full capacity and excess water, from rain, snowmelt, or other sources flow over the land. This is a major component of the water cycle or the hydrological cycle.
I think what happens is that the Cyclin component of the MPF is degraded. MPF or mitosis promoting factor, consists of two important cell cycle regulatory protein called the cyclin and cyclin dependent kinases (CDK). The cdk and the cyclins are the major control switches for the cell cycle, causing the cell to move from G1 to S or G2 to M.
That thing is called abrasion.