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Soil is a mixture made up of four main ingredients. Choose the correct list of ingredients.
a. tiny pieces of rock, humus, air and sand
b. humus, or dead plant material, clay, water, and salts.
c. tiny pieces of rock, air, water, and humus or dead plant material
d. air, water, tiny pieces of rock, and manure.
What is c. tiny pieces of rock, air, water, and humus or dead plant material