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It is a sedimentary rock made up of loosely structured, rough grains of rock.
A periodic climate pattern that occurs across the tropical Pacific Ocean every five years.
One third of the continents is covered with desert. Today, desertification is a growing problem.
The circumference of the Earth has already been calculated in ancient Egypt. The calculations...
A glacier is a large body of ice in constant, slow motion down a hillside.
The weather can be forecast with different meteorological instruments.
Karst formations include dolines and dripstones.
Lateral compressive forces cause rocks to form folds. This is how fold mountains are formed.