The soils of tropical rain forests tend to be nutrient-poor due to:
a. extensive wind erosion.
b. the fact that nutrient minerals are stored primarily in the vegetation.
c. removal of native plants, largely grasses, depleting the nutrient minerals.
d. sediment washing into streams from intact forests.
e. poor crop rotation practices in slash-and-burn agriculture.

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Explanation:

B. the fact that nutrient minerals are stored primarily in the vegetation.

no

explanation:

since the earth is flattened at the poles and bulges at the equator, geodesy represents the figure of the earth as an oblate spheroid. the oblate spheroid, or oblate ellipsoid, is an ellipsoid of revolution obtained by rotating an ellipse about its shorter axis.

81 is a composite number.