| A | B |
|---|
| contiguous | joined together inside a common boundary |
| coral reef | formed from skeletons of small sea animals |
| megalopolis | almost continuous line of urban settlements |
| secede | to withdraw from the national government |
| recycling | reusing materials instead of throwing them away |
| landfills | areas where trash companies dump collected waste |
| ethnic group | people who share a culture |
| navigable | rivers wide and deep enough to allow passage of ships |
| free enterprise | people who own their businesses with limited government control |
| immigrants | people who move to a new country to make a new home |
| colony | overseas settlement tied to a parent country |
| suburbs | smaller communities surrounding a larger city |
| land bridge | ice sheet that connected Asia and North America |
