حل ت 1 ص 71

A-Throughout the world, deserts are created because pastures near arid lands heavily are grazed and trampled
B- Around towns, adjacent forest belts are denuded by people in their search for firewood
C- More productive plants are introduced into semi-arid lands. As a result, indigenous plants necessary for the maintenance of the soil are nudged out
D- Many people think that desertification is caused only by a change in climate, but the truth is that deserts are provoked by human actions
E- Because of intensive production of cash crops like cotton and groundnuts, soil nutrients are dissipated and the topsoil is eroded by wind and water
F- A long time ago, history was made in the deserts
G- Today, about 140 million people are threatened by the spread of the desert caused through the interaction of climatic fluctuations and man’s abuse of his environment
H- Desertification must be stopped now, otherwise deserts will be transformed into a curse for man soon
I- These civilizations were built in deserts because people knew how to live in harmony with nature
J- At least two great civilizations were established there

1--------F
J--------2

I---------3
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D-------5
A-------6
C-------7
E-------8
B-------9
H-------10

A long time ago, history was made in the deserts.At least two great civilizations were established there.These civilizations were built in deserts because people knew how to live in harmony with nature.Today, about 140 million people are threatened by the spread of the desert caused through the interaction of climatic fluctuations and man’s abuse of his environment.Many people think that desertification is caused only by a change in climate, but the truth is that deserts are provoked by human actions.Throughout the world, deserts are created because pastures near arid lands heavily are grazed and trampled.More productive plants are introduced into semi-arid lands. As a result, indigenous plants necessary for the maintenance of the soil are nudged out.Because of intensive production of cash crops like cotton and groundnuts, soil nutrients are dissipated and the topsoil is eroded by wind and water.Around towns, adjacent forest belts are denuded by people in their search for firewood.Desertification must be stopped now, otherwise deserts will be transformed into a curse for man soon