How do governments affect migration

Using complete sentences, describe the central economic problem facing all humans. why does this require people to make choices? how can this result in opportunity costs?

Why are nongovernmental organizations important? check all that applya. they are private institutions that aid the work of government. b. they often fill in gaps between government-funded services. c. they are private institutions that attack government policyd. they citizens by acting as watch dogs over elected officials

The graph below plots the temperature and luminosity of stars on the main sequence.