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 for pyramids of energy/3 qhld-g ;risjjfp5y xp t/5o) rqew;n,2v.x.
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 measures for e,er gd3y vij3cbjlv +v3 / +(kcgq07qqnergy but do not include area and time, which is how p+g7q3ic j(q30bc3vk+,d egl/ vvy qrjroductivity is measured 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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