本题目来源于试卷: Interaction & Interdependence C.9 Transfers of Energy & Matter，类别为 IB生物学
[单选题]
What units are typically used for pyramj * gba8vm20klids of energy?to:isr(3 u2 vd
A. Calories
B. Kilocalories
C. $kJm^{-2}$
D. $kJm^{-2}y^{-1}$
参考答案: D
本题详细解析:
Explanation: Calories (Choice A) and Kilocalories (Choice B) are measures for energy but do not include area and time which is how productivity is measured in an ecosystem. $kJm^{−2}$ (Choice C) does include the area but not time. To see energy values over a specified time, usually a year, the units $kJm^{−2}y^{−1}$ are used.
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