If you’re talking about supply and demand, demand is how much people want of something, and the suppliers how much of it is available. If there is more demand then there is supply, the price of the product will go up. If there is more supplied and there is demand, the price will go down.
Answer: Sedentary agriculture develops.
People hunt and gather food.
Farming villages grow.
Cities develop.
Explanation: Think of the latest things we have and go back from that
I think that is it safe to say (I mean by this: check if it's among your options) that both individual and international trade are voluntary exchange of goods -both parties have to agree on it without being forced to it. Also they should be mutually beneficial - otherwise the two parties would have have agreed!
Because Germany allied with them and agreed to take part in the war