Soil structure is important for plant growth, regulating the movement of air and water, influencing root development and affecting nutrient availability. Good quality soils are friable (crumbly) and have fine aggregates so the soil breaks up easily if you squeeze it.
Answer:
transgression
Explanation:
In this case we will have deeper sea sediments (shales and limestones) being deposited on top of continentally-derived beach sediments (sand). This forms a sequence (from bottom to top) of: sand to shale to limestone. This is an indication of marine transgression
The answer is:
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[C]: Mercury and Venus.
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Mercury would be "Planet A"; and Venus would be "Planet B".