How does the author best develop the central idea of paragraph 3? A
by comparing and contrasting examples of velocity, kinetic energy, and potential energy along with examples of how all three are used at amusement parks.
B
by explaining the importance of velocity and gravity.
C
by defining and providing examples of the two types of energy used on roller coasters along with a formula of how students can calculate the energy.
D
by offering a hint that amusement parks are fun for students.

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