Which two materials comprise the Earth's core?
A. Calcium and magnesium
B. Iron and nickel
C. Iron and magnesium
D. Lead and zinc
Answer: B
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The refraction of sound is due to changes in wave
A. speed. B. frequency. C. direction. D. all of the above
After a NAPL contaminant reaches the subsurface, the most important remedial action is:
a. source control b. containment c. pump and treat d. biodegradation
All of the following are likely effects of deforestation except
A. increased rate of soil erosion. B. increased rate of destruction of plant and animal habitats. C. increased runoff into rivers and streams. D. increased rate at which carbon dioxide is extracted out of the atmosphere.
Which of the following is true of isozymes?
A) Their amino acid sequences are mirror images of one another. B) They are a pair of enzymes which must both be present for enzyme activity to occur. C) They are different forms of the same enzyme found in different tissues. D) None of the above is true.