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]
Name the correct units for rek 2fgz/dz :6i(ohjdk x rf5a.a glf/+1prer*ttng3;7i9e (m -q*wy rpdkjsenting productivity in an ecosystem.
A. $gm^{-2}$
B. $gyr^{-1}$
C. $Jm^{-2}$
D. $gm^{-2}yr^{-1}$
参考答案: D
本题详细解析:
Productivity shows the flo(hhu dq16r 5aq*y(vv zw of energy and is therefore measured as $gm^{-2}yr^{-1}$OR$Jm^{-2}yr$. Biomass shows a standing crop and is therefore measured as $gm^{-2}$
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