In 1977 ecologists Stephen Hubbell and Leslie Johnson recorded adramaticexample of how social interactions can produce andenforceregularspacing in apopulation. They studied competition andnestspacing in populations of stingless bees intropicaldry forests in Costa Rica. Though these bees do nosting,rivalcolonies of somespeciesfight fiercely overpotentialnesting sites.

Stingless bees areabundantintropicaland subtropical environments, where they gathernectarandpollenfrom a widevarietyof flowers. They generallynestin trees and live in colonies made up of hundreds to thousands of workers. Hubbell and Johnson observed that somespeciesof stingless bees are highlyaggressiveto members of theirspeciesfrom other colonies, while otherspeciesare not. Aggressivespeciesusuallyforagein groups and feed mainly on flowers thatoccurin high-density clumps. Nonaggressivespeciesfeed singly or in small groups and on more widely distributed flowers.

Hubbell and Johnson studied severalspeciesof stingless bees todeterminewhether there is a relationship betweenaggressivenessand patterns ofcolonydistribution. They predicted that the colonies ofaggressivespecieswould showregulardistributions, while those of nonaggressivespecieswould showrandomor closely grouped (clumped)distribution. They concentrated their studies on a thirteen-hectaretractoftropicaldry forest that containednumerousnests of ninespeciesof stingless bees.

Though Hubbell and Johnson were interested in how beebehaviormightaffectcolonydistributions, they recognized that theavailabilityofpotentialnestsites for colonies could alsoaffectdistributions. So as one of the first steps in their study, they mapped the distributions of treessuitablefor nesting. They found thatpotentialnesttrees were distributed randomlythroughthe study area. They also found that the number ofpotentialnestsites was much greater than the number of bee colonies. What did these measurements show the researchers? The number of colonies in the study area was not limited byavailabilityofsuitabletrees, and a clumped orregulardistributionof colonies was notdueto anunderlyingclumped orregulardistributionofpotentialnestsites.

Hubbell and Johnson mapped the nests of five of the ninespeciesof stingless bees accurately, and the nests of four of thesespecieswere distributed regularly. All fourspecieswithregularnestdistributions were highlyaggressiveto bees from other colonies of their ownspecies. The fifthspecieswas notaggressive, and its nests were randomly distributed over the study area.

The researchers also studied theprocessby which theaggressivespeciesestablishnew colonies. Their observations provide insights into the mechanisms thatestablishandmaintaintheregularnestdistributionof thesespecies. Aggressivespeciesapparently mark prospectivenestsites with pheromones, chemical substances secreted by some animals for communication with other members of theirspecies. Thepheromonesecreted by these stingless bees attracts and aggregates members of theircolonyto the prospectivenestsite; however, it also attracts workers from other nests.

If workers from two different colonies arrive at the prospectivenestat the same time, they may fight forpossession. Fights may be escalated into protracted battles. The researchers observed battles over anesttree that lasted for two weeks. Eachdawn, fifteen to thirty workers from twocompetingcolonies arrived at the contestednestsite. The workers from the two colonies faced off in two swarms and displayed and fought with each other. In the displays, pairs of bees faced each other, slowly flewverticallyto a height of about three meters, and then grappled each other to the ground. When the two bees hit the ground, they separated, faced off, and performed anotheraerialdisplay. Bees did notappearto be injured in these fights, which were apparently ritualized. The two swarms abandoned the battle at about 8 or 9 A.M. each morning, only to re-form and begin again the next day just afterdawn. While thiscontestover an unoccupiednestsite produced noobviousmortality, fights over occupied nests sometimes kill over 1,000 bees in a single battle.

Questions:
question_stem: The word “rival” in the passage is closest in leaning to
choices: tag: A
text: established

tag: B
text: competing

tag: C
text: nearby

tag: D
text: different
answer_key: B
explanation: rival: 竞争的, 对应 B 选项的 competing（竞争的）。
对应原文：Though these bees do no sting, rival colonies of some species fight fiercely over potential nesting sites.
大部分同学可能都手洗 rival 作为名词词性的意思为“对手，竞争者”。那么从这个名词词性也不难猜测其形容词词性。再者，也可以从这句话的语境来推测，主要说的是这些物种会争夺地盘，那么 rival 就是形容这些物种之间的关系的，很明显，将这一层意思表达出来的只有 B 选项。A 选项的 established（确定的，已建立的），C 选线过的 nearby（附近的），D 选项的 different（不同的）都不合适。

question_stem: According to paragraph 2, some species of stingless bees are aggressive mainly toward
choices: tag: A
text: Nonaggressive bees that forage on the same flowers

tag: B
text: Aggressive bees of other species

tag: C
text: Bees from their own colony

tag: D
text: Bees of their own species from different colonies
answer_key: D
explanation: 用 aggressive 定位到该段第三句：Hubbell and Johnson observed that some species of stingless bees are highly aggressive to members of their species from other colonies, while other species are not.这句话中明确指出了"aggressive to members of their species from other colonies"，这里说了是对它们同种的蜜蜂有攻击性，和 D 答案匹配。A 选项和原文矛盾，B 选项和原文说反，C 选项在原文中都未提及。

question_stem: According to paragraph 3, Hubbell and Johnson hypothesized that
choices: tag: A
text: the distribution pattern of bee colonies determines the degree of aggressiveness the bees display

tag: B
text: nests of nonaggressive bees have either a random or a clumped distribution, while nests of aggressive bees have a regular distribution

tag: C
text: nests of nonaggressive bees are generally both closer together and more regularly distributed than those of aggressive bees

tag: D
text: nests of aggressive bees tend to be more regular in shape than those of nonaggressive bees
answer_key: B
explanation: 没有太好的定位词，整段都在讨论他们的假设，而答案出现在该段第二句：They predicted that the colonies of aggressive species would show regular distributions, while those of nonaggressive species would show random or closely grouped (clumped) distribution.从这句话可以看出，他们预测攻击性种群有规则分布然而非攻击性种群展现出随机或成群分布。这和 B 选项完全吻合。ACD 均未在原文中提及。

question_stem: According to paragraph 4, why did Hubbell and Johnson begin their study by mapping all the potential nest sites?
choices: tag: A
text: To determine whether the availability of potential nest sites played a role in the distribution of bee colonies

tag: B
text: To know exactly where in the study area the colonies of all the different bee species were located

tag: C
text: To be sure that suitable nesting sites were equally available in all parts of study area

tag: D
text: To find out whether different species of bees preferred different types of trees as potential nest sites
answer_key: A
explanation: 用 mapping 定位到该段第二句，但是这句话只描述了 mapping 是他们的第一步骤，但是从句首的 so 可以得知，原因应该出现在前一句：
Though Hubbell and Johnson were interested in how bee behavior might affect colony distributions, they recognized that the availability of potential nest sites for colonies could also affect distributions.
该段第一句话说的是：他们意识到潜在的巢穴也会影响分布。这就是他们针对所有潜在巢穴地点进行绘图的原因。和 A 选项匹配。

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: The limited number of colonies was not due to the distribution or availability of potential nesting sites.

tag: B
text: There was no lack of suitable trees or potential nesting sites in the study area.

tag: C
text: The number of nests was directly related to the number or the distribution of suitable trees.

tag: D
text: Neither the number nor the distribution of colonies could be explained by the availability of suitable nest sites.
answer_key: D
explanation: 这句话最主要的逻辑是并列逻辑，表达了2个意思: 1. 实际巢穴的数量不受潜在数量的限制; 2 成群还是规则分布也不受潜在巢穴的分布样式的影响.A 选项错在 limited number of colonies, 原句没有提到； B 选项错在于原句意思完全无关； C 选项错在意思与原句相反； D 选项 neither nor 的2个否定完全表现出了原句中关系, 正确。

question_stem: According to paragraph 5, Hubbell and Johnson determined
choices: tag: A
text: the order in which the colonies in the study area had been established

tag: B
text: the level of aggressiveness of each of the nine species

tag: C
text: the distribution pattern of the nests of five of the nine species

tag: D
text: the number of colonies of each of the nine species
answer_key: C
explanation: 用人名定位到该段第一句前半句：Hubbell and Johnson mapped the nests of five of the nine species of stingless bees accurately, and the nests of four of these species were distributed regularly.从这句话可以看出，他们准确描述了9个巢穴中的5个巢穴的样式。这和 C 选项直接呼应，其他三个选项在原文中都没有提及。

question_stem: Why does the author indicate that “The fifth species was not aggressive, and its nests were randomly distributed over the study area”?
choices: tag: A
text: To identify research results that contradicted Hubbell and Johnson’s original hypothesis

tag: B
text: To indicate that research results confirmed that nest distribution was related to aggressiveness

tag: C
text: To introduce the hypothesis that, within the same species, not all colonies are aggressive

tag: D
text: To point out that both aggressive and nonaggressive species are equally successful at finding nest sites
answer_key: B
explanation: 这一题需要结合前文的假设来判断，在第三段中他们就假设：They predicted that the colonies of aggressive species would show regular distributions, while those of nonaggressive species would show random or closely grouped (clumped) distribution. 而阴影的这个细节及其所在的这一段都在说：4个巢穴规则样式,其蜜蜂就有攻击性; 1个巢穴随机样式, 其蜜蜂就没有表示出攻击性; 即肯定了前文的预测。所以对应 B 选项。

question_stem: The phrase “insights into” in the passage is closest in meaning to
choices: tag: A
text: tools to study

tag: B
text: opportunities for

tag: C
text: evidence of

tag: D
text: an understanding of
answer_key: D
explanation: insight： 洞察力; 领悟, 对应 D 选项的 an understanding of（对…的理解）。
对应原文：Their observations provide insights into the mechanisms that establish and maintain the regular nest distribution of these species. 首先关注 insight 的结构，in 就是进入，sight 就是视线，通过本身结构可以推断 insight 的意思。也可以从句子的前后搭配来推断，观察提供了对于机制的 insights。结合这两方面综合判断，D 选项最为合适。

question_stem: According to paragraph 6, what is one result of using pheromones to mark nest sites?
choices: tag: A
text: The use of pheromones tends to result in nest clumping.

tag: B
text: Pheromones attract animals other than bees to prospective nest sites.

tag: C
text: Pheromones tend to make bees aggressive.

tag: D
text: Pheromones secreted by bees of one colony also attract bees of other colonies
answer_key: D
explanation: 用 pheromones 去定位，定位到该段最后一句：The pheromone secreted by these stingless bees attracts and aggregates members of their colony to the prospective nest site; however, it also attracts workers from other nests.分泌出信息素吸引同一群体的成员外，同样可以吸引其他巢穴的工蜂。这和 D 选项对应。ABC 在原文中都未提及。

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

tag: B
text: transformed

tag: C
text: combined

tag: D
text: lengthened
answer_key: A
explanation: escalate：逐步增加，逐步增高，对应 A 选项 intensify (使)增强; (使)加剧。
对应原文：Fights may be escalated into protracted battles. 
首先，escal 有梯子的意思，那么就可以根据这个来判断 escsalated 的意思。当然也可以根据上下文语境来推测。上文在说如果两个群体的蜜蜂同时到达，那么它们就会打架去争夺。打架会 be escalated into 战斗。从这个意思上来看，时态是变得严重过了的。那么这四个选项中，能把这个转变体现出来的就只能是 A 选项了。B 选项的 transform（改变，转化），C 选项的 combine（结合），D 选项的 lengthen（延长）都不合适。

question_stem: Paragraph 7 supports which of the following ideas about fights over occupied nests?
choices: tag: A
text: They are more violent than battles over unoccupied nest sites.

tag: B
text: They mostly occur between colonies of different species.

tag: C
text: They are more frequent than battles over unoccupied sites.

tag: D
text: They last longer than battles over unoccupied sites do.
answer_key: A
explanation: 用 occupied 去进行定位，定位到该段最后一句：While this contest over an unoccupied nest site produced no obvious mortality, fights over occupied nests sometimes kill over 1,000 bees in a single battle.
从这句话可以看出，争夺空巢的战斗没有明显的伤亡, 然而争夺已占巢穴会造成尸横遍野。这和 A 选项匹配。BCD 在原文中都没有提及。