|
drought
|
an
unusually prolonged lack of rain. |
| equator
|
the
imaginary circle around the earth's globe equidistant from both
the North and South Poles. |
| erosion |
the
process by which material from the earth's surface is worn away
by forces such as glaciers, wind, and waves. |
| mantle
|
the layer of the earth that lies between the crust and the core.
|
| atmosphere
|
the
mass of gases surrounding the earth or any other celestial body.
|
| ocean
|
the
vast expanse of salt water covering approximately three quarters
of the earth's surface. |
| axis |
a straight line that serves as the unmoving center about which a
body or figure turns. |
| ozone
|
oxygen
in the form of molecules with three atoms, created by exposure of
oxygen to electrical discharge or ultraviolet radiation, having
a sharp smell, and being an effective oxidant for use in bleaching
and sterilizing. |
| revolution
|
orbital
motion around a given point. |
| rotation
|
the
act of turning on or around an axis. |
| terrain
|
the
natural surface features of a tract of land, esp. considered in
relation to some use or activity. |
| core |
the
center part of certain fruits, containing hard material and seeds. |
| crust
|
the
outer portion of the earth or other planet, or of a moon. |
