本题目来源于试卷: Climate Change - Causes & Impacts，类别为 IB环境系统与社会
[单选题]
Suggest an explanation for the annual fluctuations of carbon dioxide in the atmosphere.
A. There is a decrease in the combustion of fossil fuels in the summer months
B. Carbon dioxide dissolves in the oceans more rapidly during the summer months.
C. More carbon dioxide is fixed through photosynthesis in the northern hemisphere during the summer.
D. More carbon dioxide is released in the summer in the northern hemisphere.
参考答案: C
本题详细解析:
In the summer months, the rate of photosynthes6g3rp ; :jsq ff:g3hbmis increases in the northern hemisphere and more atmospheric carbon dioxide is used to make organic compounds by photosynthesizing organisms such as green plants and trees.
There is no substantial decrease in the consumption of fossil fuels during the summer, which could explain the fluctuation of carbon dioxide in the atmosphere (Option A). Carbon dioxide dissolution in the oceans cannot account for the flub jh;gfpm 3srf63::gq ctuations either (Option B).
The rate of photosynthesis is on average greater than the rate of respiration in the northern hemisphere during the summer which means more carbon dioxide is absorbed, not released at this time (Option D).
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