Directions:
　　 You are going to read a list of headings and a text about preparing in the academic community. Choose the most suitable heading from the list A-F for each numbered paragraph (41-45). The first and last paragraphs of the text are not numbered. There is one extra heading which you do not need to use. Mark your answers on ANSWER SHEET 1. (10 points)
　　 Until about two million years ago Africa’s vegetation had always been controlled by the interactions of climate; geology, soil, and groundwater conditions; and the activities of animals. The addition of humans to the latter group, however, has increasingly rendered unreal the concept of a fully developed “natural” vegetation—i.e., one approximating the ideal of a vegetational climax. (41). Early attempts at mapping and classifying Africa’s vegetation stressed this relationship: sometimes the names of plant zones were derived directly from climates. In this discussion the idea of zones is retained only in a broad descriptive sense.
　　 (42). In addition, over time more floral regions of varying shape and size have been recognized. Many schemes have arisen successively, all of which have had to take views on two important aspects: the general scale of treatment to be adopted, and the degree to which human modification is to be comprehended or discounted.
　　 (43). Quite the opposite assumption is now frequently advanced. An intimate combination of many species—in complex associations and related to localized soils, slopes, and drainage—has been detailed in many studies of the African tropics. In a few square miles there may be a visible succession from swamp with papyrus, the grass of which the ancient Egyptians made paper and from which the word “paper” originated, through swampy grassland and broad-leaved woodland and grass to a patch of forest on richer hillside soil, and finally to juicy fleshy plants on a nearly naked rock summit.
　　 (44). Correspondingly, classifications have differed greatly in their principles for naming, grouping, and describing formations: some have chosen terms such as forest, woodland, thorn-bush, thicket, and shrub for much of the same broad tracts that others have grouped as wooded savanna (treeless grassy plain) and steppe (grassy plain with few trees). This is best seen in the nomenclature, naming of plants, adopted by two of the most comprehensive and authoritative maps of Africa’s vegetation that have been published: R. W. J. Keay’s Vegetation Map of Africa South of the Tropic of Cancer and its more widely based successor, The Vegetation Map of Africa, compiled by Frank White. In the Keay map the terms “savanna” and “steppe” were adopted as precise definition of formations, based on the herb layer and the coverage of woody vegetation; the White map, however, discarded these two categories as specific classifications. Yet any rapid absence of savanna as in its popular and more general sense is doubtful.
　　 (45). However, some 100 specific types of vegetation identified on the source map have been compressed into 14 broader classifications.
　　 [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.

　　答案
　　41.F 42.A 43.C 44.G 45.D
　　總體分析
　　本文是一篇介紹非洲植被研究的科普性文章。
　　第一段：在非洲植被的圖形繪制及其分類中很早就重視了植被與氣候之間的密切關(guān)系。
　　第二段：隨著人們對(duì)非洲植物的了解增加，對(duì)植物的命名、分類和繪制圖形變得更加具體，許多有關(guān)植物區(qū)域的規(guī)劃也被提出來(lái)。
　　第三段：現(xiàn)在人們更強(qiáng)調(diào)非洲植物的多樣性而非一致性。
　　第四段：學(xué)者們對(duì)非洲草地發(fā)展的原因，對(duì)植物群系的命名、歸類以及描述的原則都存在分歧。
　　第五段：介紹現(xiàn)在非洲植被圖譜對(duì)植物的歸類法。
　　[A] 隨著人們對(duì)植物了解的增加，對(duì)植物的命名、分類和繪制圖形也更加具體。
　　[B] 在高降水量的地區(qū)，大草原的植被因周期性的火災(zāi)而得以保存。
　　[C] 非洲東部植被被認(rèn)為有很大的一致性。
　　[D] 現(xiàn)在的植物圖譜及植物分類都受懷特圖譜的影響。
　　[E] 影響植被發(fā)展的幾個(gè)因素。
　　[F] 敘述了影響植被的氣候因素。
　　[G] 學(xué)者們對(duì)于導(dǎo)致非洲草地發(fā)展的原因，存在很大的分歧。
　　試題精解
　　41.[精解] 本題考查的知識(shí)點(diǎn)是：段落內(nèi)一致性原則+上下文的銜接
　　本題空格出現(xiàn)在第一段中，應(yīng)起到承上啟下的作用。上文提到了影響非洲植被的多種因素，并強(qiáng)調(diào)人類活動(dòng)對(duì)植被氣候的影響�？崭裣挛奶岬皆缙趯�(duì)非洲植被的研究重視植物帶與氣候的關(guān)系�？梢�(jiàn)，該段主要圍繞“氣候”與“非洲植被”展開(kāi)論述。預(yù)測(cè)空格處的內(nèi)容應(yīng)和段落主題保持一致。[E]出現(xiàn)了關(guān)鍵詞“climatic”和“vegetation”，但它主要論述的是“氣候帶”，而非“氣候”。[F]出現(xiàn)了關(guān)鍵詞“climate”和“vegetation”。其中however一詞表明與上文構(gòu)成轉(zhuǎn)折關(guān)系，從“強(qiáng)調(diào)人類活動(dòng)的影響”轉(zhuǎn)向“強(qiáng)調(diào)氣候的影響”。[F]最后出現(xiàn)的belts of vegetation與空格下文plant zones是同義表達(dá)，相互呼應(yīng)。
　　42.[精解] 本題考查的知識(shí)點(diǎn)是：內(nèi)容的銜接
　　本題空格出現(xiàn)在第二段開(kāi)始。下文的特征詞in addition表明空格部分與下文存在遞進(jìn)關(guān)系。下文指出，當(dāng)人們發(fā)現(xiàn)了更多不同的植物區(qū)域時(shí)，許多規(guī)劃接連被提出。[A]中“隨著人們對(duì)植物了解的增加(more has become known of …)”與下文中“人們發(fā)現(xiàn)更多形狀和大小不一的植物區(qū)域(more … have been recognized)”內(nèi)容很接近，出現(xiàn)了銜接。從[A]提到的“植物命名、分類和繪制圖形的具體化”到下文“治理植物區(qū)域的規(guī)劃的提出”也存在著遞進(jìn)關(guān)系。
　　43.[精解] 本題考查的知識(shí)點(diǎn)是：內(nèi)容的銜接
　　本題空格出現(xiàn)在第三段開(kāi)始。下文的第一句話指出，現(xiàn)在，人們常常提出完全相反的假設(shè)。由此可知，空格處論述的內(nèi)容應(yīng)與下文相反。從第三段末句“在很小的面積里都可能出現(xiàn)多種植被類型”的論述可知，下文應(yīng)主要論述物種的多樣性。與此能夠形成對(duì)照的是[C]，它強(qiáng)調(diào)了植被的一致性(uniformity)。
　　44.[精解] 本題考查的知識(shí)點(diǎn)是：內(nèi)容的銜接
　　本題空格出現(xiàn)在第四段開(kāi)始。下文特征詞correspondingly(相應(yīng)地)表明空格部分與下文存在因果關(guān)系。此外，下文中出現(xiàn)了some和others兩個(gè)代詞，指代不明確，需要通過(guò)空格處的內(nèi)容將其具體化。下文首先指出，有關(guān)植物群系的命名、歸類以及描述原則是大相徑庭的。接著以學(xué)者對(duì)地帶的不同命名為例予以說(shuō)明。因此下文主要論述的是學(xué)者在植物研究中存在的分歧。[G]論述的正是這方面的內(nèi)容，它指出學(xué)者們對(duì)導(dǎo)致非洲草地發(fā)展的原因存在分歧。[G]中的grasslands與下文的savanna和steppe呼應(yīng)，下文some和others都指的是[G]中的scholars。具有干擾性的是[A]，它出現(xiàn)了與下文相同的字眼“naming”、“classification”、“mapping”等，但它論述的是“非洲植物種類”，而且最后出現(xiàn)的是“可能出現(xiàn)的氣候”，這些都無(wú)法與下文構(gòu)成很好的銜接。因此[G]為正確項(xiàng)。
　　45.[精解] 本題考查的知識(shí)點(diǎn)是：上下文的銜接+詞語(yǔ)的呼應(yīng)
　　本題空格出現(xiàn)在第五段開(kāi)始。下文however一詞表明空格部分與下文構(gòu)成轉(zhuǎn)折關(guān)系。下文提到，源圖中100種植物具體類別被簡(jiǎn)化為14種涵蓋更廣的類別。由此可知，空格部分應(yīng)出現(xiàn)與“圖”或“植物類別”有關(guān)的內(nèi)容。符合要求的是[D]，其中the White map與第四段提到的Frank White呼應(yīng)，its extensive annotations與下文100 specific types呼應(yīng)。

　　核心詞匯或超綱詞匯
　　(1)vegetation(n.)(統(tǒng)稱)植物;(尤指某地或環(huán)境的)植被，植物群落，草木
　　(2)current(n.)(海洋或江河的)水流，潮流，氣流;電流;思潮，潮流
　　(3)mapping(n.)(地圖等)圖形的繪制
　　(4)discount(v.)認(rèn)為不重要，不重視，不全信;打折出售
　　(5)localized(a.)在小范圍內(nèi)的，局部的，如a ~ infection局部感染
　　(6)on balance權(quán)衡起來(lái)，兩相比較，如~ I think we should benefit by adopting the scheme.(權(quán)衡起來(lái)，我們采用這個(gè)方案應(yīng)該會(huì)受益。)
　　(7)formation(n.)組成物，形成物，如massive rock ~s塊狀巖層
　　(8)nomenclature(n.)(尤指某學(xué)科的)命名法
　　全文翻譯
　　直到大約200萬(wàn)年以前，非洲的植被總是被這些因素所影響：氣候的交互作用，地質(zhì)、土壤和地下水的條件，以及動(dòng)物的活動(dòng)。然而，人類活動(dòng)的出現(xiàn)擴(kuò)大了動(dòng)物活動(dòng)的影響，并不斷使充分發(fā)展的“自然”植被——即，近似理想的植被氣候——的構(gòu)想變得不現(xiàn)實(shí)。但是，廣義上說(shuō)，氣候仍然是影響植被的主要因素。區(qū)域性的降水帶、緯度的反射以及暴露于截然不同的大西洋和印度洋氣流之下，使相應(yīng)的植被帶的出現(xiàn)成為可能。有關(guān)非洲植被的圖形繪制及其分類的早期努力就十分重視這種相關(guān)性：有時(shí)植物帶的名稱直接源于氣候。這里討論的“帶”的概念僅限于廣義和描述性的含義。
　　當(dāng)人們對(duì)非洲好幾萬(wàn)植物種類以及其復(fù)雜的生態(tài)了解得更多時(shí)，植物的命名、分類和繪制圖形也變得更加具體，開(kāi)始強(qiáng)調(diào)實(shí)際存在的而不是推測(cè)可能出現(xiàn)的氣候。此外，隨著時(shí)間的推移，人們發(fā)現(xiàn)了更多形狀和大小不一的植物區(qū)域。因此，許多規(guī)劃一個(gè)接一個(gè)地被提出，它們都涉及兩個(gè)重要方面的觀點(diǎn)：將要采取的治理手段的一般范圍以及人類的影響將要被理解或忽視的程度。
　　曾經(jīng)，在對(duì)非洲土地的科學(xué)治理中，其植被的一致性被認(rèn)為比同時(shí)期如果在西歐或美國(guó)進(jìn)行土地治理所能普遍接受的更大�，F(xiàn)在，人們常常提出完全相反的假設(shè)。在許多有關(guān)非洲熱帶地區(qū)的研究中，多個(gè)物種的密切結(jié)合——復(fù)雜的相互聯(lián)系以及與局部的土壤、坡度和排水條件的關(guān)系——已經(jīng)被詳細(xì)地給予了說(shuō)明。在幾平方英里內(nèi)，就可以看得見(jiàn)植被的更替性：從長(zhǎng)有紙草的沼澤(紙草是古埃及人用來(lái)做紙的草，“紙”這個(gè)詞就來(lái)源于它)，穿過(guò)沼澤草地、闊葉樹林和草到在肥沃的山腰土上長(zhǎng)著的一片樹林，最后到幾乎光禿禿的巖石山頂上生長(zhǎng)的肉質(zhì)多汁的植物。
　　人類在非洲活動(dòng)的時(shí)間被認(rèn)為比在其它任何洲都要長(zhǎng)�？偟膩�(lái)說(shuō)，所有活動(dòng)的結(jié)果都傾向于減少森林覆蓋面積和增加草地面積。但是在地區(qū)層面上，關(guān)于是自然還是人為導(dǎo)致了大多數(shù)非洲草地的發(fā)展，學(xué)者們存在很大的分歧。相應(yīng)地，這些學(xué)者在他們命名、歸類以及描述植物群系的原則上也是大相徑庭。對(duì)于幾乎同樣寬廣的地帶，一些學(xué)者將其歸類為非洲大草原(沒(méi)有樹木)和西伯利亞大草原(樹木稀疏)，而另一些學(xué)者則選用如森林、林地、荊棘、灌木叢、灌木這樣的術(shù)語(yǔ)來(lái)描述。這種差異性在已出版的兩幅有關(guān)非洲植被最全面最權(quán)威的圖譜所采用的植物術(shù)語(yǔ)中可見(jiàn)一斑。這兩幅圖是：R. W. J·凱伊編寫的《北回歸線以南的非洲植被圖》和后來(lái)出版的資料來(lái)源更為廣泛的由富蘭克·懷特編輯的《非洲植被圖》。以木本植群的覆蓋率和草本層為依據(jù)，凱伊的圖采用“非洲大草原”和“西伯利亞大草原”對(duì)植物群系進(jìn)行精確定義;而在懷特的圖中，卻并不采用這兩種具體的分類方法。然而，普遍而廣泛意義上的非洲大草原的迅速缺失卻是令人質(zhì)疑的。
　　現(xiàn)在使用的非洲植被圖譜及普通的植被歸類法都沿用懷特的圖譜及其廣博的注解。但是，源圖中確認(rèn)的100種植物的具體類別被簡(jiǎn)化為14種涵蓋更廣的類別。
　　干擾項(xiàng)
　　[B] 在高降水量地區(qū)，比如非洲東部，大草原的植被因周期性的火災(zāi)而得以保存。雨季末的大火燃燒了干草，火燒退了森林植被，阻礙了樹木和灌木的滋生，并促進(jìn)了新草的生長(zhǎng)。
　　[E] 非洲植被帶與氣候帶有著緊密的聯(lián)系，赤道以南和赤道以北出現(xiàn)了結(jié)構(gòu)非常相似的植被帶。氣候帶、降雨量和降雨的季節(jié)性分布的差異一起對(duì)植被發(fā)展構(gòu)成了最重要的影響。