tree is a good example of a competitor。 A massive oak claims its ground for 200 years or more； outcompeting all other would…be canopy trees by casting a dense shade and drawing up any free water in the soil。 The leaves of an oak tree taste foul because they are rich in tannins； a chemical that renders them distasteful or indigestible to many organisms。 The tannins are part of the defense mechanism that is essential to longevity。 Although oaks produce thousands of acorns； the investment in a crop of acorns is small compared with the energy spent on building leaves； trunk； and roots。 Once an oak tree becomes established； it is likely to survive minor cycles of drought and even fire。 A population of oaks is likely to be relatively stable through time； and its survival is likely to depend more on its ability to withstand the pressures of competition or predation than on its ability to take advantage of chance events。 It should be noted； however； that the pure opportunist or pure competitor is rare in nature； as most species fall between the extremes of a continuum； exhibiting a blend of some opportunistic and some competitive characteristics。
与opportunist相对应，本段以橡树为例，同样从“形态、生存时间、种群数量、能量分配”等方面介绍植物中的competitor的特点：
1。 具有强大的体态，能生存更长时间，不会将大部分能量用于繁殖；
2。 由于生存时间较长，且能抵抗恶劣环境，因此橡树的种群数量相对稳定。
二、阅读题目类型
托福阅读的题型主要分为以下几类：
Factual Information（事实信息题）
Negative Factual Information（否定排除题）
Inference（推论题）
Rhetorical Purpose（修辞题）
Vocabulary（词汇题）
Reference（指代题）
Sentence Simplification（句子简化题）
Insert Text（插入文字题）
Fill in a Table（图表题）
Prose Summary（总结题）
下面，我们将为考生提供一些解题的思路：
1。 查找信息类题目
这类问题主要考查考生对原文信息的理解，比如事实信息题（Factual Information）和否定排除题（Negative Factual Information）。这类题目要求选出与文中内容相符或不符的一项。这类问题的提问方式通常为：
According to the passage； 。。。
Based on the information in。。。
例如：
Reading Passage
Based on the information in paragraph 1； which of the following best explains the term wind farms？
Farms using windmills to pump water
Research centers exploring the uses of wind
Types of power plant common in North Dakota
Collections of wind turbines producing electric power
In 1994 there were nearly 20；000 wind turbines worldwide； most grouped in clusters called wind farms that collectively produced 3；000 megawatts of electricity。 Most were in Denmark （which got 3 percent of its electricity from wind turbines） and California （where 17；000 machines produced 1 percent of the state’s electricity； enough to meet the residential needs of a city as large as San Francisco）。 In principle； all the power needs of the United States could be provided by exploiting the wind potential of just three states — North Dakota； South Dakota； and Texas。
根据题干中的paragraph 1和wind farms这两个信息，我们可以快速定位到原文第一段的相应内容：In 1994 there were nearly 20；000 wind turbines worldwide； most grouped in clusters called wind farms that collectively produced 3；000 megawatts of electricity。 从这句话中可以得知wind turbines grouped in clusters 即是文中提问的wind farm，所以选第4项。
除了事实信息题和否定排除题以外，在做图表题时也需要利用查找定位的方法，回到原文中寻找答案。
2。 推论题
对于推论题（Inference）这类在文中没有直接表达的问题，可以根据文中陈述的已知信息推断出来。通常这类问题会以这样的形式提问：
What can be inferred from the passage？
比如下面的例子：
Reading Passage
What are the bones found in the Lascaux caves believed to indicate？
Wild animals sometimes lived in the cave chambers。
Artists painted pictures on both walls and bones。
Artists ground them into a fine powder to make paint。
Artists developed special techniques for painting the walls。
In Southwest France in the 1940’s； playing children discovered Lascaux Grotto； a series of narrow cave chambers that contain huge prehistoric paintings of animals。 Many of these beasts are as large as 16 feet （almost 5 meters）。 Some follow each other in solemn parades； but others swirl about； sideways and upside down。 The animals are bulls； wild horses； reindeer； bison； and mammoths outlined with charcoal and painted mostly in reds； yellow； and browns。 Scientific analysis reveals that the colors were derived from ocher and other iron oxides ground into a fine powder。 Methods of applying color varied： some colors were brushed or smeared on rock surfaces and others were blown or sprayed。 It is possible that tubes made from animal bones were used for spraying because hollow bones； some stained with pigment； have been found nearby。
这道题询问从洞穴中发现的骨头可以得到什么结论。根据关键词bones，可以定位到该段的末尾句。
根据tubes made from animal bones were used for spraying以及some stained with pigment，可以知道将空心的骨头当做绘画工具的方法。故选第4项。
3。 词汇及语言修辞类题目
托福阅读考试的修辞题（Rhetorical Purpose）、词汇题（Vocabulary）、指代题（Reference）、句子简化题（Sentence Simplification）和插入文字题（Insert Text）都是与文字和措辞有关的题目。这类题目主要考查考生的语言运用能力。
其中，修辞题主要考查考生是否了解某句话的特定意图，而词汇题则考查某个词语或短语的具体意思。通常考查的内容都会对文章理解起到至关重要的作用。
指代类问题考查某个代词指代的对象，句子简化题则要求考生选出与原文中某个句子含义相同的答案。这两道题目都比较简单。
插入文字题则会提供一个新的句子，考生需要将它插入到文章中合适的位置，这道题可以检验考生的逻辑性。
4。 理解文章概要类问题
理解文章概要类问题属于托福阅读考试中的新题型，包含总结题（Prose Summary）和图表题（Fill in a Table），这两道题的难度比较大，考查考生理解一篇文章的写作意图以及整理文章框架、理清文章层次的能力。
其中，总结题需要考生根据文中出现的内容推断答案，这道题目会提供6个选项，考生要选出最能概括文章内容的3项。在做这道题目时，考生要具备理解及总结重要信息的能力。要注意，不要选择那些仅陈述文章某一细节的选项，因为这些细节的作用通常只是支持观点的论据。正确的选项应该是概括性的陈述。请看下面的例子：
Urban Climates
The city is an extraordinary processor of mass and energy and has its own metabolism。 A daily input of water； food； and energy of various kinds is matched by an output of sewage； solid waste； air pollutants； energy； and materials that have been transformed in some way。 The quantities involved are enormous。 Many aspects of this energy use affect the atmosphere of a city； particularly in the production of heat。
In winter the heat produced by a city can equal or surpass the amount of heat available from the Sun。 All the heat that warms a building eventually transfers to the surrounding air； a process that is quickest where houses are poorly insulated。 But an automobile produces enough heat to warm an average house in winter； and if a house were perfectly insulated； one adult could also produce more than enough heat to warm it。 Therefore； even without any industrial production of heat； an urban area tends to be warmer than the countryside that surrounds it。
The burning of fuel； such as by cars； is not the only source of this increased heat。 Two other factors contribute to the higher overall temperature in cities。 The first is the heat capacity of the materials that constitute the city； which is typically dominated by concrete and asphalt。 During the day； heat from the Sun can be conducted into these materials and stored — to be released at night。 But in the countryside materials have a significantly lower heat capacity because a vegetative blanket prevents heat from easily flowing into and out of the ground。 The second factor is that radiant heat coming into the city from the Sun is trapped in two ways： by a continuing series of reflections among the numerous vertical surfaces that buildings present and by the dust dome the cloudlike layer of polluted air that most cities produce。 Shortwave radiation from the Sun passes through the pollution dome more easily than outgoing longwave radiation does； the latter is absorbed by the gaseous pollutants of the dome and reradiated back to the urban surface。
Cities； then； are warmer than the surrounding rural areas； and together they produce a phenomenon known as the urban heat island。 Heat islands develop best under particular conditions associated with light winds； but they can form almost any time。 The precise configuration of a heat island depends on several factors。 For example； the wind can make a heat island stretch in the direction it blows。 When a heat island is well developed； variations can be extreme； in winter； busy streets in cities can be 17℃ warmer than the side streets。 Areas near traffic lights can be similarly warmer than the areas between them because of the effect of cars standing in traffic instead of moving。 The maximum differences in temperature between neighboring urban and rural environments is called the heat…island intensity for that region。 In general； the larger the city； the greater its heat…island intensity。 The actual level of intensity depends on such factors as the physical layout； population density； and productive activities of a metropolis。
The surface…atmosphere relationships inside metropolitan areas produce a number of climatic peculiarities。 For one thing； the presence or absence of moisture is affected by t