[单选题]
The above data obtained from Mauna Loa show trends in atmospheric CO$_2$ concentrations. What conclusions can be made from this graph?
I. There is an annual fluctuation of carbon dioxide concentration in the atmosphere.
II. There is a continuous increase in the average concentration of carbon dioxide in the atmosphere over the years.
III. Increased use of fossil fuels has caused an increase in carbon dioxide in the atmosphere as recorded in Mauna Loa.
A. I only
B. I and II only
C. I and III only
D. I, II and III
参考答案:
B
本题详细解析:
The data show an annual fluctuation in the concentration of carbon dioxide (I) and a constant increase in average concentration over the many years measured (II).
Choice A includes annual fluctuations but not a constant increase in carbon dioxide.
Choice C includes a conclusion about annual fluctuations but also the conclusion that says increased use of fossil fuels has caused the increase in carbon dioxide in the atmosphere (III) which cannot be determined based on this graph.
Choice D includes all three conclusions and since conclusion III is incorrect, it is not the right choice.
