There isevidenceofagriculturein Africapriorto 3000 B.C. It may have developed independently, but many scholars believe that thespreadofagricultureand ironthroughoutAfrica linked it to themajorcenters of the Near East andMediterraneanworld. The drying up of what is now the Saharadeserthad pushed many peoples to the south into sub-Sahara Africa. These peoples settled at first inscatteredhunting-and-gathering bands, although in some places near lakes and rivers, people who fished, with a moresecurefoodsupply, lived in largerpopulationconcentrations. Agricultureseems to have reached these people from the Near East, since the firstdomesticatedcrops were millets and sorghums whose origins are not African but west Asian. Once the idea of plantingdiffused, Africans began to develop their own crops, such as certain varieties of rice, and they demonstrated a continued receptiveness to new imports. The proposed areas of thedomesticationof African crops lie in abandthat extends from Ethiopiaacrosssouthern Sudan to West Africa. Subsequently, other crops, such as bananas, were introduced from Southeast Asia.

Livestockalso came from outside Africa. Cattlewere introduced from Asia, as probably weredomesticsheep and goats. Horses were apparently introduced by the Hyksos invaders of Egypt (1780-1560 B.C.) and thenspreadacrossthe Sudan to West Africa. Rock paintings in the Saharaindicatethat horses and chariots were used to traverse thedesertand that by 300-200 B.C., there weretraderoutesacrossthe Sahara. Horses were adopted by peoples of the West African savannah, and later their powerfulcavalryforces allowed them tocarveout large empires. Finally, thecamelwas introduced around the firstcenturyA.D. This was an importantinnovation, because thecamel’s abilities tothriveinharshdesertconditions and to carry large loads cheaply made it aneffectiveandefficientmeans oftransportation. Thecameltransformed thedesertfrom abarrierinto a still difficult, but moreaccessible,routeoftradeand communication.

Iron came from West Asia, although its routes ofdiffusionweresomewhatdifferent than those ofagriculture. Most of Africa presents acuriouscase in which societies moved directly from a technology of stone to iron without passingthroughtheintermediatestageofcopperorbronzemetallurgy, although some early copper-working sites have been found in West Africa. Knowledge of iron making penetrated into the forest and savannahs of West Africa atroughlythe same time that iron making was reaching Europe. Evidenceof iron making has been found in Nigeria, Ghana, and Mali.

Thistechnologicalshiftcauseprofoundchanges in thecomplexityof African societies. Iron represented power. In West Africa the blacksmith who made tools and  weapons had an important place in society, often withspecialreligiouspowers and functions. Iron hoes, which made the land moreproductive, and iron weapons, which made the warrior more powerful, hadsymbolicmeaning in a number of West Africa societies. Those who knew the secrets of making iron gainedritualand sometimespoliticalpower.

Unlike in the Americas, wheremetallurgywas a very late and limiteddevelopment, Africans had iron from arelativelyearlydate, developingingeniousfurnaces to produce the high heat needed for production and to control theamountofairthat reached thecarbonand ironorenecessary for making iron. Much of Africa moved right into the Iron Age, taking thebasictechnology and adapting it tolocalconditions and resources.

Thediffusionofagricultureand later of iron was accompanied by a great movement of people who may have carried these innovations.These people probably originated in eastern Nigeria.Theirmigrationmay have been set inmotionby an increase inpopulationcaused by a movement of peoples fleeing thedesiccation, or drying up, of the Sahara.They spoke a language, proto-Bantu (“Bantu” means “the people”), which is the parent tongue of a language of a large number of Bantu languages still spokenthroughoutsub-Sahara Africa.Why and how these peoplespreadout into central and southern Africa remains a mystery, but archaeologists believe that their iron weapons allowed them toconquertheir hunting-gathering opponents,

who still used stone implements.Still, theprocessis uncertain, and peacefulmigration—orsimplyrapiddemographicgrowth—may have also caused the Bantuexplosion. These people probably originated in eastern Nigeria. Theirmigrationmay have been set inmotionby an increase inpopulationcaused by a movement of peoples fleeing thedesiccation, or drying up, of the Sahara. They spoke a language, proto-Bantu (“Bantu” means “the people”), which is the parent tongue of a language of a large number of Bantu languages still spokenthroughoutsub-Sahara Africa. Why and how these peoplespreadout into central and southern Africa remains a mystery, but archaeologists believe that their iron weapons allowed them toconquertheir hunting-gathering opponents,

who still used stone implements. Still, theprocessis uncertain, and peacefulmigration—orsimplyrapiddemographicgrowth—may have also caused the Bantuexplosion.

Questions:
question_stem: The word “diffused” in the passage is closest in meaning to
choices: tag: A
text: emerged

tag: B
text: was understood

tag: C
text: spread

tag: D
text: developed
answer_key: C
explanation: diffuse: 扩散。A 是出现；B 是被理解；C 是传播，扩散；D 是发展。根据词意，正确的是 C 选项。对应原文：Once the idea of planting diffused, Africans began to develop their own crops, such as certain varieties of rice, and they demonstrated a continued receptiveness to new imports.前一句说农业是从近东过来的，那些作物都不是非洲的，接着就说一旦种植的 idea 怎么了非洲，非洲人开始了自己研发自己的作物。不是非洲的东西到了非洲，所以是扩散或者蔓延，不是单纯的出现，emerge 不对；只理解 idea 肯定不行，要去做，understood 不对；原文的 idea 没有更深入一步的意思，develop 不对。

question_stem: According to paragraph 1, why do researchers doubt that agriculture developed independently in Africa?
choices: tag: A
text: African lakes and rivers already provided enough food for people to survive without agriculture.

tag: B
text: The earliest examples of cultivated plants discovered in Africa are native to Asia.

tag: C
text: Africa’s native plants are very difficult to domesticate.

tag: D
text: African communities were not large enough to support agriculture.
answer_key: B
explanation: B 以 developed independently 和 agriculture 做关键词定位至第二句，但这句话只说非洲的农业与近东以及地中海地区相关，如果知道近东是亚洲的一部分和非洲的一部分的总称的话，答案就出来了，B 正确；不知道的话往后看，下面还有一句提到了 agriculture，就是第五句说农业是从亚洲来的，因为那些作物不是非洲原产的，所以答案是 B

question_stem: In paragraph 1, what does the author imply about changes in the African environment during this time period?
choices: tag: A
text: The climate was becoming milder, allowing for a greater variety of crops to be grown.

tag: B
text: Although periods of drying forced people south, they returned once their food supply was secure.

tag: C
text: Population growth along rivers and lakes was dramatically decreasing the availability of fish.

tag: D
text: A region that had once supported many people was becoming a desert where few could survive.
answer_key: D
explanation: D,  以 changes of African environment 做关键词定位至原文第三句，注意题目中的关键词原文没有，但原文中的 drying up of what is now the Sahara desert 就是一个环境变化。说干旱把这些人赶到了撒哈拉以南地区，也就是说这个变化使得他们原来住的地方不能住了，所以 D 正确；A 说气候变得温和，与原文相反；B 说他们回到原来的地方，与原文说的定居在南部非洲相反；C 没有相关信息

question_stem: According to paragraph 2, camels were important because they
choices: tag: A
text: were the first domesticated animal to be introduced to Africa

tag: B
text: allowed the people of the West African savannahs to carve out large empires

tag: C
text: helped African peoples defend themselves against Egyptian invaders

tag: D
text: made it cheaper and easier to cross the Sahara
answer_key: D
explanation: C  以 camel 做关键词定位至倒数第二句，说 camel 在一世纪引入，然后就说这个非常重要，后面就是重要的原因，所以 D 正确

question_stem: According to paragraph 2, which of the following were subjects of rock paintings in the Sahara?
choices: tag: A
text: Horses and chariots

tag: B
text: Sheep and goats

tag: C
text: Hyksos invaders from Egypt

tag: D
text: Camels and cattle
answer_key: A
explanation: 以 rock painting 做关键词定位至第四句：Rock paintings in the Sahara indicate that horses and chariots were used to traverse the desert and that by 300-200 B.C., there were trade routes across the Sahara. 这里说了 horse 和 chariot 被用来穿越沙漠，所以很明显答案是 A。

question_stem: What function does paragraph 3 serve in the organization of the passage as a whole?
choices: tag: A
text: It contrasts the development of iron technology in West Asia and West Africa.

tag: B
text: It discusses a non-agricultural contribution to Africa from Asia.

tag: C
text: It introduces evidence that a knowledge of copper working reached Africa and Europe at the same time.

tag: D
text: It compares the rates at which iron technology developed in different parts of Africa.
answer_key: B
explanation: B 问整段在文章中的作用，看首句。说铁也是从西亚来的，但跟农业扩散的线路不同，所以答案是 B，亚洲对非洲的除农业之外的影响；原文没有比较西非和西亚的 iron 技术，重点是描述非洲的，所以 A 错；C 和 D 只是段落中的小细节，不足以呈现整段的作用。

question_stem: The word “profound” in the passage is closest in meaning to
choices: tag: A
text: fascinating

tag: B
text: far-reaching

tag: C
text: necessary

tag: D
text: temporary
answer_key: B
explanation: profound: 深刻的，意义深远的。A 是吸引人的；B 是深远的，广泛的；C 是必须的；D 是暂时的。所以 B 的 far-reaching 是正确答案。对应原文：This technological shift cause profound changes in the complexity of African societies. Iron represented power.第三段整个在说铁是怎么到非洲的，第四段一开头就说这个技术给非洲带来什么样的变化，本篇文章的题目就与铁有关，肯定铁是很重要的，而且从后文也能看出来这些变化很重要，影响是深远的，所以 temporary 一定不对，fanscinating 迷人的变化和 necessary 必要的变化从后文没法看出来，所以都不对。

question_stem: The word “ritual” in the passage is closest in meaning to
choices: tag: A
text: military

tag: B
text: physical

tag: C
text: ceremonial

tag: D
text: permanent
answer_key: C
explanation: ritual: 仪式的，常规的。A 是军事的；B 是物理的，身体的；C 是仪式的；D 是永久的。所以 C 的 ceremonial 正确。对应原文：Those who knew the secrets of making iron gained ritual and sometimes political power.原句说那些懂得制铁工艺的人会获得什么权利，有时候甚至会获得政治上的权利，永久的和身体的，自然的都不能和政治并列，所以 B 的 physical 跟 D 的 permanent 错；MS 军事和政治是能并列的，但之前有提到 symbolic meaning，叫象征意义，所以 C 更合适。

question_stem: According to paragraph 4, all of the following were social effects of the new metal technology in Africa EXCEPT:
choices: tag: A
text: Access to metal tools and weapons created greater social equality.

tag: B
text: Metal weapons increased the power of warriors.

tag: C
text: Iron tools helped increase the food supply.

tag: D
text: Technical knowledge gave religious power to its holders.
answer_key: A
explanation: A EXCEPT 题，排除法，A 没说，所以选；B 的 warriors 在倒数第二句，正确，不选；C 中的 food supply 虽然原文没有，但原文倒数第二句有 land more productive，说明这个选项对，不选；D 的 religious power 在最后一句，正确，不选

question_stem: Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.
choices: tag: A
text: While American iron makers developed the latest furnaces, African iron makers continued using earlier techniques.

tag: B
text: Africans produced iron much earlier than Americans, inventing technologically sophisticated heating systems.

tag: C
text: Iron making developed earlier in Africa than in the Americas because of the ready availability of carbon and iron ore.

tag: D
text: Both Africa and the Americas developed the capacity for making iron early, but African metallurgy developed at a slower rate.
answer_key: B
explanation: B 本句的结构是，和美洲不同，非洲人制铁比较早，后面自 developing 开始全是状语后置，不看。A 错，因为原文没说美洲人用的是最新的技术，只是说他们炼铁比较晚；B 的结构与原文完全一致，对；C 的前半句是对的，但后面给出的原因完全是瞎凑的，错；原文将非洲和美洲进行比较，而 D 将两者放在一起，所以 D 错。

question_stem: The word “fleeing” in the passage is closest in meaning to
choices: tag: A
text: afraid of

tag: B
text: displaced by

tag: C
text: running away from

tag: D
text: responding to
answer_key: C
explanation: flee: 逃跑。A 是害怕；B 是被取代；C 是逃离；D 是反应。所以 C 正确。对应原文：Their migration may have been set in motion by an increase in population caused by a movement of peoples fleeing the desiccation, or drying up, of the Sahara. 原句说迁徙是由人口增加导致的，然后这些人是为怎么样撒哈拉沙漠的干旱才迁移的，逃避是正确意思；因为已经干了，所以不是害怕，afraid of 不对；人不能被干旱替代，所以 displace by 不对；respond to 答复完全不靠谱。

question_stem: Paragraph 6 mentions all of the following as possible causes of the “Bantu explosion” EXCEPT
choices: tag: A
text: superior weapons

tag: B
text: better hunting skills

tag: C
text: peaceful migration

tag: D
text: increased population
answer_key: B
explanation: A 在倒数第二句：Why and how..., but archaeologists believe that their iron weapons allowed them to conquer their hunting-gathering opponents, who still used stone implements. A 正确，不选；B 错，选，因为原文只说武器能够帮他们战胜打猎的对手，没说他们打猎的技术好；C 和 D 都在最后一句，正确，不选：Still, the process is uncertain, and peaceful migration—or simply rapid demographic growth—may have also caused the Bantu explosion.