推理题（Inference）考察考生理解和感知作者观点或者立场的能力，要求考生需要根据句子间的逻辑暗示进行更深层次的推断。常见的题干如下：

The author of the passage implies that X ...

Which of the following can be inferred from paragraph 1 about X

1.因果不用推理

如果推理题的题干中出现why， the reason， so that等体现因果关系的词，则本种推断题无需“推测”，在段中找到正确体现原因/结果之处再进行paraphrase即可解出正确答案。

Paragraph 6: The contribution of geothermal energy to the world's energy future is difficult to estimate. Geothermal energy is in a sense not renewable, because in most cases the heat would be drawn out of a reservoir much more rapidly than it would be replaced by the very slow geological processes by which heat flows through solid rock into a heat reservoir. However, in many places (for example, California, Hawaii, the Philippines, Japan, Mexico, the rift valleys of Africa)the resource is potentially so large that its future will depend on the economics of production. At present, we can make efficient use of only naturally occurring hot water or steam deposits. Although the potential is enormous, it is likely that in the near future geothermal energy can make important local contributions only where the resource is close to the user and the economics are favorable, as they are in California, New Zealand, and Iceland. Geothermal energy probably will not make large-scale contributions to the world energy budget until well into the twenty-first century, if ever.  

（P21-P1 Geothermal Energy）

In paragraph 6, the author implies that in California, Hawaii, the Philippines, Japan, Mexico, and the rift valleys of Africa the potential size of the geothermal resource is so large that

A.It might be economically worth developing these sites even though geothermal energy is not renewable

B.These sites will be the first geothermal energy sites to be developed with new technology

C.These sites are likely to make a large-scale contribution to the world energy budget in the twenty-first century

D.It does not matter whether they have naturally occurring deposits of hot water or steam

题干中的“so … that”表示因果 和段中“so large that”对应，原段说的结果是“它将会依赖产出经济”和A中的“economically”相对应，所以得A。

Paragraph 3： If colonizers produce short-lived reproductive propagules, they must produce very large numbers unless they have an efficient means of dispersal to suitable new habitats. Many plants depend on wind for dispersal and produce abundant quantities of small, relatively short-lived seeds to compensate for the fact that wind is not always a reliable means of reaching the appropriate type of habitat. Alternative strategies have evolved in some plants, such as those that produce fewer but larger seeds that are dispersed to suitable sites by birds or small mammals or those that produce long-lived seeds. Many forest plants seem to exhibit the latter adaptation, and viable seeds of pioneer species can be found in large numbers on some forest floors. For example, as many as 1,125 viable seeds per square meter were found in a 100-year-old Douglas fir/western hemlock forest in coastal British Columbia. Nearly all the seeds that had germinated from this seed bank were from pioneer species. The rapid colonization of such sites after disturbance is undoubtedly in part a reflection of the large seed bank on the forest floor. 

（32-P1 Plant Colonization）

What can be inferred from paragraph 3 about the reason that large seeds are dispersed by birds or small animals rather than by wind?   

A.Large seeds are easier for birds and animals to see than are the small seeds dispersed by the wind.

B.Large seeds are too heavy for the wind to disperse.

C.Large seeds cannot be eaten by birds and animals.

D.Large seeds are short-lived and thus require a more efficient means of dispersal than small seeds do.

题干问的“是鸟不是风传播的reason”，原段中“those that produce fewer but larger seeds that are dispersed to suitable sites”描述了鸟传播的好处（优于风传播），所以答案为B。

Paragraph1： In the open sea, animals can often find food reliably available in particular regions or seasons (e g., in coastal areas in springtime). In these circumstances, animals are neither constrained to get the last calorie out of their diet nor is energy conservation a high priority. In contrast, the food levels in the deeper layers of the ocean are greatly reduced, and the energy constraints on the animals are much more severe. To survive at those levels, animals must maximize their energy input, finding and eating whatever potential food source may be present.

（45-P3 Feeding Strategies in the Ocean）

What can be inferred from paragraph 1 about why energy conservation is not a high priority for ocean animals in coastal waters during the spring?    

A.Those animals are least active during the spring

B.Those animals have a plentiful supply of food

C.Those animals have to expend energy to avoid predators.

D.Those animals store energy during the colder seasons.

题干中的why表示因果，所以本题的infer实际上无需推断，理解原段做出paraphrase即可。题干问及“为什么春天不节能？”原文划线处说的是“动物在某些地区或某些季节可找到稳定的食物源（如春天的沿海地区）,在这种环境下，动物既不…也不….”，所以 答案是B“动物食物充足”。

2.段意

如果infer的题干中没有表示因果的词，仅有infer的对象，我们可以根据段意中心来推理。

Paragraph 6:Seasonal migration is another form of escape, especially for large mammals or birds. The term retreat is applied to the short-term escape behavior of desert animals, and it usually assumes the pattern of a daily rhythm. Birds shelter in nests, rock overhangs, trees, and dense shrubs to avoid the hottest hours of the day, while mammals like the kangaroo rat burrow underground.  

（26-P2  Survival of Plants and Animals in Desert Conditions）

It can be inferred from paragraph 6 that all of the places desert animals retreat to  

A.Provide shade from the sun 

B.Sometimes become crowded 

C.Are places where supplies of food are plentiful 

D.Leave the animals vulnerable to predators

本段讨论的是“retreat是一种短期逃跑行为，表现出昼夜节律（daily rhythm）”那么段中出现的例子也要体现“昼夜节律（daily rhythm）”这一点，只有A能体现这一点，故选A。

Paragraph 1:  Pollen, a powdery substance, which is produced by flowering plants and contains male reproductive cells, is usually carried from plant to plant by insects or birds, but some plants rely on the wind to carry their pollen. Wind pollination is often seen as being primitive and wasteful in costly pollen and yet it is surprisingly common, especially in higher latitudes. Wind is very good at moving pollen a long way; pollen can be blown for hundreds of kilometers, and only birds can get pollen anywhere near as far. The drawback is that wind is obviously unspecific as to where it takes the pollen. It is like trying to get a letter to a friend at the other end of the village by climbing onto the roof and throwing an armful of letters into the air and hoping that one will end up in the friend's garden. For the relatively few dominant tree species that make up temperate forests, where there are many individuals of the same species within pollen range, this is quite a safe gamble. If a number of people in the village were throwing letters off roofs, your friend would be bound to get one. By contrast, in the tropics, where each tree species has few, widely scattered individuals, the chance of wind blowing pollen to another individual is sufficiently slim that animals are a safer bet as transporters of pollen. Even tall trees in the tropics are usually not wind pollinated despite being in windy conditions. In a similar way, trees in temperate forests that are insect pollinated tend to grow as solitary, widely spread individuals. 

（P45-P2  Wind Pollination）

 Which of the following can be inferred from paragraph 1 about pollen production?

A.Pollen production requires a significant investment of energy and resources on the part of the plant.

B.The capacity to produce pollen in large quantities is a recent development in the evolutionary history of plants. 

C.Plants in the tropics generally produce more pollen than those in temperate zones. 

D.The highest levels of pollen production are found in plants that depend on insects or birds to carry their pollen. 

段首讨论了风授粉的特点，其中之一是“primitive and wasteful in costly pollen”对应A的“requires a significant investment of energy and resources”，而B，D在原段均未提；C 偷换概念：原段中是没有比较的。

Paragraph 2： The Egyptians were not far behind in developing writing, but we cannot follow the history of their writing in detail because they used a perishable writing material. In ancient times the banks of the Nile were lined with papyrus plants, and from the papyrus reeds the Egyptians made a form of paper; it was excellent in quality but, like any paper, fragile. Mesopotamia’s rivers boasted no such useful reeds, but its land did provide good clay, and as a consequence the clay tablet became the standard material. Though clumsy and bulky it has a virtue dear to archaeologists: it is durable. Fire, for example, which is death to papyrus paper or other writing materials such as leather and wood, simply bakes it hard, thereby making it even more durable. So when a conqueror set a Mesopotamian palace ablaze, he helped ensure the survival of any clay tablets in it. Clay, moreover, is cheap, and forming it into tablets is easy, factors that helped the clay tablet become the preferred writing material not only throughout Mesopotamia but far outside it as well, in Syria, Asia Minor, Persia, and even for a while in Crete and Greece. Excavators have unearthed clay tablets in all these lands. In the Near East they remained in use for more than two and a half millennia, and in certain areas they lasted down to the beginning of the common era until finally yielding, once and for all, to more convenient alternatives. 

（TPO46-P1 The Origins of Writing）

What can be inferred from paragraph 2 about clay as a writing material? 

A.It had to be baked before it could be written on 

B.Its good points outweighed its bad points.

C.Its durability was its most important feature for its users.

D.It was not available in Egypt.

题干infer的对象是clay，本段介绍了它的特点：clumsy VS durable，cheap 所以根据段意推理出B。A，D与原文矛盾， C强加“最（）”。

3.两段间的“推理”

Paragraph 2: When experimental populations are set up under simple laboratory conditions, the predator often exterminates its prey and then becomes extinct itself, having nothing left to eat. However, if safe areas like those prey animals have in the wild are provided, the prey population drops to low level but not extinction. Low prey population levels then provide inadequate food for the predators, causing the predator population to decrease. When this occurs, the prey population can rebound. In this situation the predator and prey population may continue in this cyclical pattern for some time.

Paragraph 3:  Population cycles are characteristic of small mammals, and they sometimes appear to be brought about by predators. Ecologists studying hare populations have found that the North American snow shoe hare follows a roughly ten-year cycle. Its numbers fall tenfold to thirty in a typical cycle, and a hundredfold change can occur. Two factors appear to be generating the cycle: food plants and predators. 

（27-P3 Predator-Prey Cycles）

Which of the following can be inferred from paragraphs 2 and 3 about the small mammals that experience population cycles?

A.Their population cycles are not affected by predators.

B.Their predators’ populations periodically disappear. 

C.They typically undergo ten-year cycles. 

D.They have access to places safe from predators.  

段2讨论了population cycles 产生的条件：“if safe areas like those prey animals have in the wild are provided”；段3紧接着说population cycle是small mammals的特点，也就是说，small mammals也会处于段2的“safe areas”这一条件，关于safe的选项可推理出D。A与原文矛盾：population cycles受predators影响；B 未提及； C 信息错位：原文的hare经历十年的循环，不是所有small mammals。

Paragraph 5：In the 1980s, John Graves studied two populations of closely related fishes, one population from the Atlantic side of isthmus, the other from the Pacific side. He compared four enzymes found in the muscles of each population. Graves found that all four Pacific enzymes function better at lower temperatures than the four Atlantic versions of the same enzymes. This is significant because Pacific seawater is typically 2 to 3 degrees cooler than seawater on the Atlantic side of isthmus. Analysis by gel electrophoresis revealed slight differences in amino acid sequence of the enzymes of two of the four pairs. This is significant because the amino acid sequence of an enzyme is determined by genes.

Paragraph 6：Graves drew two conclusions from these observations. First, at least some of the observed differences between the enzymes of the Atlantic and Pacific fish populations were not random but were the result of evolutionary adaptation. Second, it appears that closely related populations of fishes on both sides of the isthmus are starting to genetically diverge from each other. Because Graves’s study of geographically isolated populations of isthmus fishes offers a glimpse of the beginning of a process of gradual accumulation of mutations that are neutral or adaptive, divergences here might be evidence of allopatric speciation in process.   

（31-P1 Speciation in Geographically Isolated Populations）

It can be inferred from paragraph 5 and 6 that the reason Graves concluded that some of the differences between the Pacific and Atlantic enzymes were not random was that   

A.Each of the Pacific enzymes works better in cooler waters

B.The Enzymes of the Atlantic fish populations had not changed since the formation of the Isthmus of Panama

C.Gel electrophoresis showed that the changes benefited both the Atlantic and the Pacific fish populations

D.The differences between the enzymes disappeared when the two fish populations were experimentally switched to other side of the isthmus

题干中的关键词“the differences between the Pacific and Atlantic enzymes were not random”是第6段的conclusions之一，那么答案在第5段中寻找。体现题干中“difference between…”即为段5的“all four Pacific enzymes function better at lower temperatures than the four Atlantic versions of the same enzymes”，所以选A。本题跨段找答案，但也遵循之前提到的“原因”的推理不用推，paraphrase相应句群即可。

4.难题

Darwin’s theory was that the succession from one coral reef type to another could be achieved by the upward growth of coral from a sinking platform, and that there would be a progression from a fringing reef, through the barrier reef stage until, with the disappearance through subsidence (sinking) of the central island, only a reef-enclosed lagoon or atoll would survive. A long time after Darwin put forward this theory, some deep boreholes were drilled in the Pacific atolls in the 1950s. The drill holes passed through more than a thousand meters of coral before reaching the rock substratum of the ocean floor, and indicated that the coral had been growing upward for tens of millions of years as Earth's crust subsided at a rate of between 15 and 51 meters per million years. Darwin s theory was therefore proved basically correct. There are some submarine islands called guyots and seamounts, in which subsidence associated with sea-floor spreading has been too speedy for coral growth to keep up. 

（47-P3 Coral Reefs）

Which of the following can be inferred from paragraph 3 about the Pacific atolls? 

A. They were once fringing reefs around the coasts of islands. 

B. They were first observed by Darwin during his voyage on the Beagle. 

C. They will eventually become fringing reefs. 

D. They are located where the ocean floor does not sink. 

题中的infer的对象是Pacific atolls。段中Pacific atolls出现在描述“from a fringing reef”（起点）到“only a reef-enclosed lagoon or atoll would survive”（终点）之后，Pacific atolls为“终点”，那么它的“起点”为 “fringing reef”，所以选A。阅读中段内句与句中间的信息是相关联，这种关联性也是考生们做推断题的依据点之一。

Paragraph2. In the near-surface layers, there are many large, fast carnivores as well as an immense variety of planktonic animals, which feed on plankton (small, free-floating plants or animals) by filtering them from currents of water that pass through a specialized anatomical structure. These filter-feeders thrive in the well-illuminated surface waters because oceans have so many very small organisms, from bacteria to large algae to larval crustaceans. Even fishes can become successful filter-feeders in some circumstances. Although the vast majority of marine fishes are carnivores, in near-surface regions of high productivity the concentrations of larger phytoplankton (the plant component of plankton) are sufficient to support huge populations of filter-feeding sardines and anchovies. These small fishes use their gill filaments to strain out the algae that dominate such areas. Sardines and anchovies provide the basis for huge commercial fisheries as well as a food resource for large numbers of local carnivores, particularly seabirds. At a much larger scale, baleen whales and whale sharks are also efficient filter-feeders in productive coastal or polar waters, although their filtered particles comprise small animals such as copepods and krill rather than phytoplankton. 

（45-P3 Feeding Strategies in the Ocean）

What can be inferred from paragraph 2 about fish?  

A.Most fish feed on plankton.

B.Fish tend to avoid well-illuminated areas.

C.Most fish species are not filter-feeders.

D.Few fish species are successful in the near-surface layers.

本段讨论光线充足的海水表面小生物体多，“甚至鱼在某些条件下都成功成为filter-feeder”说明鱼通常条件下不是filter-feeder，这样就推理出C选项。

综上所述阅读中的推理题可以不用推，paraphrase即可；根据段意推理；两段之间的推理题一定要找好内在联系（如“条件”），遇到难的推理题可根据段内信息的联系（如“递进”，“终点”）做好选择。