問題詳情

     Apart from the polar regions, it is difficult to imagine a more inhospitable environment on Earththan a desert. A desert is an arid region 55 annual rainfall generally under 5 inches, insufficient toallow anything 56 very sparse or small vegetation to grow. Semi-desert is usually taken as havingfrom 5 to 10 inches of annual precipitation, 57 growth of scattered low shrubs. These, of course,are very rough definitions. A number of formulae based on annual rainfall and temperature havebeen 58 , but none so far has been universally accepted. On the above 59 , roughly a fifth of theland surface of the Earth is desert or semi-desert.
55
(A) at
(B) by
(C) for
(D) with

參考答案

無參考答案

內容推薦

內容推薦