问题描述：
英语翻译
On the other hand,rainfall increased in the interior of western Africa,and the northern limit of the tsetse fly,an insect fatal to cattle,moved south.So the herders shifted South...
If the water table intersects the land surface,ground water will flow out unto the surface at springs,either to be collected or to subsequently flow along a drainage.
On the other hand,rainfall increased in the interior of western Africa,and the northern limit of the tsetse fly,an insect fatal to cattle,moved south.So the herders shifted South...
If the water table intersects the land surface,ground water will flow out unto the surface at springs,either to be collected or to subsequently flow along a drainage.
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