本题目来源于试卷: IB ESS Unit 2: Ecosystems & Ecology，类别为 IB环境系统与社会
[单选题]
State the units used fory6 ndz4e )obg: pyramids ofa3a2kavsr5m ksf * 7d5 energy.
A. Calories
B. Kilocalories
C. $KJm^{-2}$
D. $KJm^{-2}y^{-1}$
参考答案: D
本题详细解析:
Calories (option A) and kilocalories option B) are measuo go uhe8 7r zer..yb/r;7,koeres for energy but do not include area and time, which is how productivity is 87.7h o eo;ur/ ory ke.g,zerbmeasured in an ecosystem. Option C does include the area but not the time. To see energy values over a specified time, usually a year, the units $KJm^{-2}y^{-1}$ are used
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