| A | B |
|---|
| hypothesis | an idea to test |
| test | to try or experiment |
| crust | the outer, cooler part of the Earth |
| mantle | the thick warm middle layer of the Earth |
| core | the hot center of the Earth |
| ocean | a large area of salty water like Pacific or Atlantic |
| continents | a large area of land like Asia or North America |
| plates | pieces of the Earth's crust that move |
| igneous | rock that comes from fire |
| sedimentary | rock made from small pieces of rock, soil and shells |
| magma | hot melted rock under the Earth's surface |
| lava | hot melted rock on the Earth's surface |
| gravity | a force that pulls objects together |
| atmosphere | the layer of air that surrounds the Earth |
| equator | an imaginary line around the middle of the Earth |
| precipitation | water like snow, fog or rain |
| axis | an imaginary line through the middle of the Earth (from north pole to south pole) |
| revolve | to travel around another object |
| season | summer, fall winter and spring |
| moon | an object that travels around a planet |
| gravity | a force that pulls objects together |
| resource | anything you use (like coal, food or sunlight) |
| renewable | possible to replace (like wind or water) |
| nonrenewable | impossible to completely replace (like coal or other fossil fuels) |
| global | covering the whole planet |
| habitat | a place where an organism lives and reproduces |
| desert | a very dry area on Earth |
| pollution | dirty air, water or land |
| protect | keep from being damaged |
| recycle | to use a material again (like plastic or metal) |
