a huge, moving mass of ice
wearing away of the Earth's surface by water, or wind
a flat, sandy area where a river enters an ocean
a high, flat landform
a way to draw the curved areas of the Earth on a flat surface
related to regions near the equator; a tropical climate is very warm and moist
coal, oil, or natural gas that formed over millions of years from the remains of plants and tiny animals
a resource that can be replaced as it is used
a resource that cannot be replaced by natural resources or is replaced extremely slowly
Please allow access to your computer’s microphone to use Voice Recording.
We can’t access your microphone!
Click the icon above to update your browser permissions above and try again
Reload the page to try again!
Press Cmd-0 to reset your zoom
Press Ctrl-0 to reset your zoom
It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.
Your microphone is muted
For help fixing this issue, see this FAQ.