You use highly accurate techniques to learn the time when lots and lots of different volcanic rocks solidified from melted rock. You do this for many different rocks across the continents, and many different rocks across the sea floor. You will find that (note that "older" rocks are those that solidified more years ago, and "younger" rocks are those that solidified fewer years ago.):

Which of the following countries has declared itself nuclear free

In the following diagram, four different index fossils are labeled: which of the labeled fossils comes from the oldest organism? a b c d

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