| A | B |
|---|
| population | total number of people |
| demographer | person who studies populations |
| population density | average number of people in a square mile |
| birth rate | number of live births per 1,000 people |
| death rate | number of deaths per 1,000 people |
| life expectancy | average number of years people live |
| Green Revolution | new farming methods, varieties of food, new protection against insects |
| migration | people moving from one place to another |
| immigrants | people who move from one country to another |
| push-pull theory | conditions cause people to migrate |
| famine | hunger |
| urbanization | growth of cities as people migrate |
| rural | having to do with countryside |
| urban | having to do with a city |
