托福阅读真题Official 52 Passage 3（七）

托福阅读真题Official 52 Passage 3（七）

Early Food Production in Sub-Saharan Africa

At the end of the Pleistocene(around 10,000 B.C.),the technologies of food production may have already been employed on the fringes of the rain forests of western and central Africa,where the common use of such root plants as the African yam led people to recognize the advantages of growing their own food.The yam can easily be resprouted if the top is replanted.This primitive form of“vegeculture”(cultivation of root and tree crops)may have been the economic tradition onto which the cultivation of summer rainfall cereal crops was grafted as it came into use south of the grassland areas on the Sahara’s southern borders.

As the Sahara dried up after 5000 B.C.,pastoral peoples(cattle herders)moved southward along major watercourses into the savanna belt of West Africa and the Sudan.By 3000 B.C.,just as ancient Egyptian civilization was coming into being along the Nile,they had settled in the heart of the East African highlands far to the south.The East African highlands are ideal cattle country and the home today of such famous cattle-herding peoples as the Masai.The highlands were inhabited by hunter-gatherers living around mountains near the plains until about 3300 B.C.,when the first cattle herders appeared.These cattle people may have moved between fixed settlements during the wet and dry seasons,living off hunting in the dry months and their own livestock and agriculture during the rains.

As was the case elsewhere,cattle were demanding animals in Africa.They required water at least every 24 hours and large tracts of grazing grass if herds of any size were to be maintained.The secret was the careful selection of grazing land,especially in environments where seasonal rainfall led to marked differences in graze quality throughout the year.Even modest cattle herds required plenty of land and considerable mobility.To acquire such land often required moving herds considerable distances,even from summer to winter pastures.At the same time,the cattle owners had to graze their stock in tsetse-fly-free areas.The only protection against human and animal sleeping sickness,a disease carried by the tsetse fly,was to avoid settling or farming such areas—a constraint severely limiting the movements of cattle-owning farmers in eastern and central Africa.As a result,small cattle herds spread south rapidly in areas where they could be grazed.Long before cereal agriculture took hold far south of the Sahara,some hunter-gatherer groups in the savanna woodlands of eastern and southern Africa may have acquired cattle,and perhaps other domesticated animals,by gift exchange or through raids on herding neighbors.

Contrary to popular belief,there is no such phenomenon as“pure”pastoralists,a society that subsists on its herds alone.The Saharan herders who moved southward to escape drought were almost certainly also cultivating sorghum,millet,and other tropical rainfall crops.By 1500 B.C.,cereal agriculture was widespread throughout the savanna belt south of the Sahara.Small farming communities dotted the grasslands and forest margins of eastern West Africa,all of them depending on what is called shifting agriculture.This form of agriculture involved clearing woodland,burning the felled brush over the cleared plot,mixing the ash into the soil,and then cultivating the prepared fields.After a few years,the soil was exhausted,so the farmer moved on,exploiting new woodland and leaving the abandoned fields to lie fallow.Shifting agriculture,often called slash-and-burn,was highly adaptive for savanna farmers without plows,for it allowed cereal farming with the minimal expenditure of energy.

The process of clearance and burning may have seemed haphazard to the uninformed eye,but it was not.Except in favored areas,such as regularly inundated floodplains,tropical Africa’s soils were of only moderate to low fertility.The art of farming was careful soil selection,that is,knowing which soils were light and easily cultivable,could be readily turned with small hoes,and would maintain their fertility over several years’planting,for cereal crops rapidly remove nitrogen and other nutrients from the soil.Once it had taken hold,slash-and-burn agriculture expanded its frontiers rapidly as village after village took up new lands,moving forward so rapidly that one expert has estimated it took a mere two centuries to cover 2,000 kilometers from eastern to southern Africa.

Question 13 of 14

Look at the four squares[■]that indicate where the following sentence could be added to the passage.Southern Africa was,however,relatively free of tsetse flies.Where would the sentence best fit?Click on a square[■]to add the sentence to the passage.

正确答案：C

题目详解

题型分类：插入句子题

题干分析：考察句子和句子之间的衔接判断（通过however这一转折词汇，可以预测出前面讲过某些地区存在舌蝇，后面有可能讲南部地区舌蝇少所造成的影响）。

选项分析：

C选项however与前一句eastern and central Africa存在tsetse flies形成转折。并且与后一句As a result，small cattle herds spread south形成因果逻辑。

A选项逻辑错误，后一句graze their stock和前一句都在说放牧对土地的要求，该处不能插句子。

B选项逻辑错误，后一句a disease carried by the tsetse fly解释了前一句需要在tsete-fly-area放牧的原因，该处不能插句子。

D选项逻辑错误，后一句south of the Sahara与前一句spread south呼应，该处不能插句子。

Question 14 of 14

Directions:An introductory sentence for a brief summary of the passage is provided below.Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage.Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage.This question is worth 2 points.

The technologies of food production may have already been employed by some sub-Saharan peoples by the end of the Pleistocene.

Answer Choices:

A.

Food production started with the cultivation of root plants and developed to include the cultivation of cereal crops.

B.

Pastoralists who moved south across the Sahara to find suitable land for cattle grazing may have also cultivated some crops for food.

C.

In order to avoid human and animal sleeping sickness,which posed a danger to herders and cattle,more and more herders took up cultivation.

D.

Hunter-gatherer groups in eastern and southern Africa raided their herding neighbors to acquire cattle and other domesticated animals.

E.

By 1500 B.C.cereal agriculture was widespread throughout the savanna belt south of the Sahara,and shifting agriculture was used effectively and widely by farmers.

F.

Slash-and-burn agriculture was initially rejected by farmers because it was too labor-intensive,but once the technique was improved,it expanded gradually to eastern and southern Africa.

正确答案：ABE

题目详解

题型分类：文章总结题

题干分析：选择概括性的正确选项。

选项分析：

A选项对应第一段重要信息。最后一句cultivation of root对应选项中的cultivation of root plants；cultivation of summer rainfall cereal crops对应选项中的cultivation of cereal crops。

B选项对应第四段重要信息，第2句moved southward to escape drought对应选项中的moved south across the Sahara to find suitable land；cultivating sorghum,millet,and other tropical rainfall crops对应选项中的cultivated some crops for food。

E选项对应第四，五段重要信息，第四段第3句By 1500 B.C.,cereal agriculture was widespread throughout the savanna belt south of the Sahara对应选项By 1500 B.C.cereal agriculture was widespread throughout the savanna belt south of the Sahara，第五段最后一句slash-and-burn agriculture expanded its frontiers rapidly...moving forward so rapidly对应选项shifting agriculture was used effectively and widely by farmers。

C选项出自第四段第一句，但原文说的是there is no such phenomenon as“pure”pastoralists，说明放牧和种植并行，而不是more and more herders took up cultivation，与原文矛盾。

D选项出自第三段最后一句话，为第三段细节。

F选项出自第四段最后一句话，但原文说的是highly adaptive for savanna farmers without plows...with the minimal expenditure of energy，而不是too labor-intensive与原文矛盾。