An important role played by humus in the soil is:
a. as a catalyst in chemical reactions by which plants extract nutrients from the soil.
b. as an improver of soil structure and water retention.
c. as a source of food for microscopic soil organisms.
d. all of these
D
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Desert locations cool off rapidly at night due to the high specific heat of sand
Indicate whether the statement is true or false
Growing awareness of environmental issues during the 20th century led to the creation of the U.S. Environmental Protection Agency in what decade?
A) The 1950s B) The 1960s C) The 1970s D) The 1980s
The Geographical arrangement of things on earth is called
a. spatial organization or distribution. b. environmental expansion. c. environmental complexity. d. cultural landscape. e. none of the above.
Depressions that result primarily from the surface or near-surface solution of rock and removal of the dissolved materials by water infiltrating downward into the subsurface are called _______________. (two words)
Fill in the blank(s) with correct word