What describes how topsoil, or A-horizons develop?
A. clay particles that are pulled upwards by plant roots
B. clay particles carried downward by infiltrating water
C. repeated flooding over long periods of time
D. accumulation of organic matter in the upper soil zone
E. reactions between water and atmospheric oxygen
Answer: D
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Which phytoplankton flourished in the Miocene, probably because of increased volcanism?
a. coccolithophores b. diatoms c. dinoflagellates d. foraminifera e. radiolarians
Most biological productivity in the ocean occurs in the aphotic zone
a. True b. False
The idea that the physical environment controls and molds the behavior of the people is called
a. environmental determinism. b. environmental possibilism. c. environmental age. d. environmental transition. e. environmental awareness.
What is the single greatest domestic and commercial use of water?
A. Watering lawns and gardens B. Rainwater harvesting C. Toilet flushing D. Electric power production