The largest land areas on Earth
Continent
Half of the Earth
Hemisphere
The stone at the top of an arch that supports the weight of other stones
Keystone
A natural feature on Earth's surface
Landform
A deep, narrow valley with steep walls
Gorge
A small river or stream that flows into a larger river
Tributary
Material found in nature that people can use
Natural Resource
Fuel found in the Earth that is made from the remains of plants or an animal from long ago
Fossil Fuel
A resource that can be replaced
Renewable Resource
Resource that can not be replaced
Nonrenewable Resource
To make soil, air, or water dirty
Pollution
To use resources carefully so that they are not wasted or destroyed
Conserve
Chemical for killing insect pests
Pesticide
The pattern of weather in a place over a long period of time
Climate
The weather that falls to Earth as rain, snow, sleet or hail
Precipitation
A variety of plants and trees
Vegetation
A place where plants and animals live
Habitat
Height of land
Elevation
The largest land areas on Earth
Continent
The stone at the top of an arch that supports the weight of other stones
Keystone
A small river or stream that flows into a larger river
Tributary
Material found in nature that people can use
Natural Resource
A resource that can be replaced
Renewable Resource
To use resources carefully so that they are not wasted or destroyed
Conserve
A place where plants and animals live
Habitat