16. How do microplastics found on the ocean floor end up in people's bodies? A. Coral reefs fail to break down the microplastics, and they end up back on beaches.
B. Humans eat sea salt containing the microplastic.
C. Humans scuba dive in areas where microplastics are visible.
D. Acid rain reacts with plastics on the ocean floor and releases them into the air.

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