Answer:
1. allocation, 2. supply and demand, 3. scarcity
Explanation:
1. Human, natural and capital are all examples of resources, but allocation is not. Instead, allocation is the amount or portion of a resource assigned to a particular recipient.
2. Command, free-market and mixed are all examples of economies, while supply and demand directs the production and goods.
3. Producers make goods or provide services to earn money. Scarcity is the state of being scarce or in short supply.