Humans cultivate plants that house bacteria in soil to convert ammonia and ammonium ions to .

1. emigration the movement of people from one place to another 2. immigration a situation in which resources are being used up at a faster rate than they can be replenished 3. migration the leaving of one's homeland to settle in a new place 4. overpopulation the movement of people to a new country 5. sustainable development a situation in which the birth rate is not sufficient to replace the existing population 6. underpopulation the ability to meet current needs without reducing the ability to meet future needs 7. unsustainable development the increase in the population of a city 8. urbanization a situation in which the number of people exceeds the available natural resources in an area

Why is carbon the backbone of liveing things

Label the following as inner or outer planets; a) has 67 moons made mostly of hydrogen and helium b) has rings c)no moons, high volcanic activity d) known as the red planet, has 2 moons e) very thin atmosphere, moons or rings