The scientist improved the validity of his experiment by providing one setup to show that it was the fertilizer that was changing the DO; rather than another unnamed variable. This is called a ____________________, and was the setup with _____ grams of fertilizer added.
A. control, 40 g
B. control, 0 g
C. constant, 40 g
D. constant, 0 g
E. independent variable, 0 g
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What is the purpose of this experiment?
A. To observe green algae growth
B. To observe changes in nitrate amounts
C. to determine whether fertilizer changes DO
D. to determine whether algae changes DO
E. to determine whether DO changes fertilizer amount
The major human causes of extinction today are
A. Poaching and habitat destruction
B. Pollution and invasive species
C. Global climate change
D. Both a and b
E. A, b, and c
According to the data in the graph, what is true about oil versus coal and natural gas consumption?
A. the increase in natural gas consumption was greater than the increase in oil
B. oil consumption was not as high as natural gas or coal consumption
C. the spike in oil consumption beginning in 1963 resulted in an exponential increase over coal or natural gas consumption
D. the consumption of coal, oil, and natural gas all occured at the same rate
E. coal and natural gas consumption spiked over oil consumption in 1965
Which of the following provides the most renewable commercial energy in the world today?
A. solar
B. oil
C. biomass
D. nuclear
E. hydroelectric
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