Fill in the Blanks EconomicsOnline version 6th Grade Econ Vocab by Morgan Velez 1 Interdependence specialization producers Opportunity economy supply Owners and workers are called . How much of something you have is . Making only some types of goods and services is . is when people or regions depend on others for certain things . cost is the cost of doing one activity compared to doing something else . The study of the system in which people make , exchange , or use things that have value is called .