49. | The highest sand dunes are found is | |||||||
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50. | The greatest variety of animal and plant species is fund in | |||||||
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51. | The layer of the earth, immediately below the crust, is called | |||||||
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52. | The highest mountains in Africa, which is not part of any mountains chain, is | |||||||
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53. | The heavier silicates named as ‘Sima’ or silica + magnesium are most abundant in the | |||||||
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