18) The concentration of carbon dioxide in the atmosphere is ________
A) a small fraction of 1%
B) approximately 10%
C) approximately 30%
D) approximately 50%
E) approximately 75%
Answer: A
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An apple and a pea at rest are simultaneously dropped in a vacuum. The apple falls to the ground
A. depends on their masses. B. sooner than the pea. C. at the same time as the pea. D. later than the pea.
Which of the following biomes are found along the 39th parallel in the United States?
a. Chaparral b. Chaparral and coniferous forest c. Chaparral, coniferous forest and desert d. Chaparral, coniferous forest, desert and prairie grassland e. Chaparral, coniferous forest, desert, prairie grassland and deciduous forest
The youngest event represented in this block diagram is
A) formation of the lowest layer.
B) deposition of the top layer.
C) erosion of a canyon by a river.
D) retreat of the seas.
____________________ occurs when crystals form in bodily fluids
Fill in the blank(s) with correct word