Explain the process of sand filtration

The process of filtration is passing water through a material such as a bed of sand. The particles are removed by sand filtration by straining, adsorption, and biological action.Sand filtration has become popular for small systems because of reliability and minimal operation and maintenance requirements.

Explanation:

the more fit you are, the faster the recovery. your heart rate drops most sharply in the first minute after you stop exercising; it should then fall about 20 beats a minute—a drop of less than 12 beats a minute is considered abnormal. this “recovery heart rate” is measured as part of an exercise stress test.