Trade involves the transfer of goods or services from one person or entity to another, often in exchange for money. A system or network that allows trade is called a market.
The product of mental labor — science — always stands far below its value, because the labor-time necessary to reproduce it has no relation at all to the labor-time required for its original production.
Karl Marx Addenda, "Relative and Absolute Surplus Value" in Economic Manuscripts (1861–63).
Climate change impacts, such as rising temperatures, prolonged droughts and extreme precipitation, are expected to affect many areas, including mountain regions. A large consortium worked to develop advanced models to quantify and predict the impact of climate change primarily on surface water.
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