Always check for understanding because if not you’ll get it will get it wrong.
Answer:
28 true. Humus: the organic component of soil, formed by the decomposition of leaves and other plant material by soil microorganisms.
29 false, Soil organic matter is the fraction of the soil that consists of plant or animal tissue in various stages of breakdown (decomposition). Most of our productive agricultural soils have between 3 and 6% organic matter. Soil organic matter contributes to soil productivity in many different ways.
B.
economic is about the economy.
political is literally what it says.
social is about the society.
i think.