In a volume of air near the earth's surface, __________ occupies 78 percent
and __________ nearly 21 percent.
a. nitrogen, oxygen
b. hydrogen, oxygen
c. oxygen, hydrogen
d. nitrogen, water vapor
e. hydrogen, helium
a
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An important condition for the formation of coal is ________
A) abundant plant and animal life in a region B) acid rich waters that reduce the organic matter to pure carbon C) decomposition of organic matter with abundant oxygen D) incomplete decomposition of organic matter due to a lack of oxygen
Shorelines are temporary geologic and topographic features. Explain this statement
What will be an ideal response?
Which best describes areas with extremely high concentrations of rare plant and animal species that are in danger of extinction without immediate protection?
A. biodiversity hot spots B. Wi-Fi hot spots C. gardens in urban areas D. biodiversity cool spots
Why is igneous an appropriate label for rocks formed from magma or lava?
A) It comes from the Latin word igneus, which means crushed. B) It comes from the Latin word igneus, which means fiery. C) It comes from the Latin word igneus, which means pressurized. D) It comes from the Latin word igneus, which means dissolved.