A= X (20) times Y (20). Multiply by your overall width (3), you get 1200.
20 x 20 x 3 = 1200
I believe that most mature soils have three soil horizons. That is Horizon A, Horizon B, and Horizon C. Horizon A, also called the top soil contains a mixture of mineral matter and organic matter, as well as many insects, fungi, and microorganisms. Horizon B, also called the sub soil, contains fine clay particles washed out of horizon A. Horizon C contains partially weathered parent material.
Genetic variation happens when one organism in the population mates with a genetically different organism. Same species, different genetics such as color or height/weight.
The answer is A because it is not like an alkaline which takes up hydrogen ions. Also having a low ph value is what causes something to become acidic so it is not B. Your answer is A
