［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.
正确答案：F
本题考查的知识点是：段落内一致性原则+上下文的衔接 本题空格出现在第一段中应起到承上启下的作用上文提到了影响非洲植被的多种因素并强调人类活动对植被气候的影响空格下文提到早期对非洲植被的研究重视植物带与气候的关系可见该段主要围绕“气候”与“非洲植被”展开论述预测空格处的内容应和段落主题保持一致［E］出现了关键词“climatic”和“vegetation”但它主要论述的是“气候带”而非“气候”［F］出现了关键词“climate”和“vegetation”其中however一词表明与上文构成转折关系从“强调人类活动的影响”转向“强调气候的影响”［F］最后出现的beltsofvegetation与空格下文plantzones是同义表达相互呼应
