The lack of plate tectonics on other planets in our solar system likely means which of the following must be true? a. No other planet has a solid crust over a moving upper mantle. b. Earth has more layers than any other planet. c. Earth is the only planet with a magnetic field. d. No other planet has a warm interior.

Match your vocabulary word to its definition. 1. emigration 2. immigration 3. migration 4. overpopulation 5. sustainable development 6. under population 7. unsustainable development 8. urbanization the movement from one place to another the number of people exceeds the available natural resources in an area leaving one's homeland to settle in a new place the increase in the population of a city the movement of people to a new country the ability to meet current needs without reducing the ability to meet future needs resources being used up at a faster rate than they can be replenished birth rate insufficient to replace the existing population