[A] As more has become known of the many thousands of African plant species and t

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[A] As more has become known of the many thousands of African plant species and their complex ecology, naming, classification, and mapping have also become more particular, stressing what was actually present rather than postulating about climatic potential.

[B] In regions of higher rainfall, such as eastern Africa, savanna vegetation is maintained by periodic fires. Consuming dry grass at the end of the rainy season, the fires burn back the forest vegetation, check the invasion of trees and shrubs, and stimulate new grass growth.

[C] Once, as with the scientific treatment of African soils, a much greater uniformity was attributed to the vegetation than would have been generally accepted in the same period for treatments of the lands of western Europe or the United States.

[D] The vegetational map of Africa and general vegetation groupings used here follow the White map and its extensive annotations.

[E] African vegetation zones are closely linked to climatic zones, with the same zones occurring both north and south of the equator in broadly similar patterns. As with climatic zones, differences in the amount and seasonal distribution of precipitation constitute the most important influence on the development of vegetation.

[F] Nevertheless, in broad terms, climate remains the dominant control over vegetation. Zonal belts of precipitation, reflection latitude and contrasting exposure to the Atlantic and Indian oceans and their currents, give some reality to related belts of vegetation.

[G] The span of human occupation in Africa is believed to exceed that of any other continent. All the resultant activities have tended, on balance, to reduce tree cover and increase grassland; but there has been considerable dispute among scholars concerning the natural versus human-caused development of most African grasslands at the regional level.

参考答案:

D本题考查的知识点是:上下文的衔接+词语的呼应本题空格出现在第五段开始。下文however一词表明空格部分与下文构成转折关系。下文提到,源图中100种植物具体类别被简化为14种涵盖更广的类别。由此可知,空格部分应出现与“图”或“植物类别”有关的内容。符合要求的是[D],其中the White map与第四段提到的Frank White呼应,its extensive annotations与下文100 specific types呼应。