一、托福考试中常见的否定形式词缀： ab-normal, contra-dict, counter-act, de-forest, dis-organized, dif-ferent, hetero-geneous, in-credible, im-moral, ir-regular, il-literate, motion-less, mis-interpret, male-volent, mal-nutrition, non-essential, no-thing, op-pose, ob-struction, re-press, un-lock, under-estimate等；
副词： no, never, not；only, barely, hardly, merely, seldom等；介词： out, without, unlike等；
TPO 03：in-evitable=un-avoidableTPO 09：in-hospitable=not suitableTPO 12：im-mobile=motion-lessTPO 15：de-ceiving=mis-leadingTPO 17：in-advertently=un-intentionallyTPO 22：un-anticipated=not expectedTPO 23：in-frequent=un-commonTPO 25：out-dated=old-fashionedTPO 27：in-tact=un-damagedTPO 30：in-numerable=count-lessTPO 45：no wonder=un-surprising
TPO 10：erratic=un-predictableTPO 11：preposterous=un-believableTPO 11：artificial=not realTPO 15：static=un-changingTPO 22：reluctant=un-willingTPO 22：accidental=un-intentionalTPO 23：astonishing=in-credibleTPO 36：chaotic=dis-organizedTPO 48：constant=un-changing
4、带色彩（形式肯定、含义否定）的形容词和动词TPO 03：pales=loses significance
TPO 15：unique among=dif-ferent from all otherTPO 19：hetero-geneous=varied
5、表示方向的介词TPO 01：out of sight=hidden（反话正说）
TPO 09：at random=without a definite pattern（正话反说）TPO 37：durable=existing for a long time without significant damage（正话反说）
例1：（TPO 4 Petroleum Resources）Although this rise of oil is almost always carefully controlled today, spouts of oil, or gushers, were common in the past.Which of the following can be inferred from paragraph 3 about gushers? ○They are unlikely to occur nowadays.
例2：（TPO 6 William Smith）Paragraph 2: This was before the steam locomotive, and canal building was at its height.3. Which of the following can be inferred from paragraph 2 about canal building? ○Canal building decreased after the steam locomotive was invented.
例3：（TPO 10 Chinese Pottery）To twentieth-century eyes, Chinese pottery may appear merely decorative, yet to the Chinese the form of each object and its adornment had meaning and significance. Only when European decorative themes were introduced did these meanings become obscured or even lost.11. Paragraph 5 suggests which of the following about the decorations on Chinese pottery? ○Their significance may have remained clear had the Chinese not come under foreign influence.
例4：（TPO 7 The Geologic History of the Mediterranean）Sediment above and below the gypsum layer contained tiny marine fossils, indicating open-ocean conditions.4．Which of the following can be inferred from paragraph 3 about the solid gypsum layer? ○It did not contain any marine fossil.
例5：（TPO 02 The Origins of Cetaceans）However, unlike the cases of sea otters and pinnipeds (seals, sea lions, and walruses, whose limbs are functional both on land and at sea), it is not easy to envision what the first whales looked like.2. Which of the following can be inferred from paragraph 1 about early sea otters? ○It is not difficult to imagine what they looked like.
例6：（TPO 5 The Origin of the Pacific Island People）After several years of cultivation and harvest by phytoremediation, the site would be restored at a cost much lower than the price of excavation and reburial, the standard practice for remediation of contaminated soils.11. It can be inferred from paragraph 6 that compared with standard practices for remediation of contaminated soils, phytoremediation ○is less suitable for soils that need to be used within a short period of time
例7：（TPO 5 The Origin of the Pacific Island People）Pacific islanders are variously thought to have come from North America, South America, Egypt, Israel, and India, as well as Southeast Asia. Many older theories implicitly deprecated the navigational abilities and overall cultural creativity of the Pacific islanders. For example, British anthropologists G. Elliot Smith and W. J. Perry assumed that only Egyptians would have been skilled enough to navigate and colonize the Pacific.5. Which of the following can be inferred from paragraph 2 about early theories of where the first inhabitants of the Pacific islands came from? ○They assumed that the peoples living in Southeast Asia did not have the skills needed to sail to the Pacific islands.
例8：（TPO 8 Extinction of the Dinosaurs）By measuring how many of these meteorites fall to Earth over a given period of time, scientists can estimate how long it might have taken to deposit the observed amount of Ir in the boundary clay. These calculations suggest that a period of about one million years would have been required. However, other reliable evidence suggests that the deposition of the boundary clay could not have taken one million years. So the unusually high concentration of Ir seems to require a special explanation.10. Paragraph 5 implies that a special explanation of Ir in the boundary clay is needed because ○the amount of Ir in the boundary clay is too great to have come from microscopic meteorites during the time the boundary clay was deposited
例1：(TPO 2 Desert Formation)
The final major human cause of desertification is soil salinization resulting from overirrigation. Excess water from irrigation sinks down into the water table. If no drainage system exists, the water table rises, bringing dissolved salts to the surface. The water evaporates and the salts are left behind, creating a white crustal layer that prevents air and water from reaching the underlying soil.9. All of the following are mentioned in the passage as contributing to desertification EXCEPT○the raising of livestock解析：C选项“insufficient irrigation”和原文“overirrigation”矛盾。
例2：（TPO 3 The Long-Term Stability of Ecosystems）
Paragraph 1: Plant communities assemble themselves flexibly, and their particular structure depends on the specific history of the area. Ecologists use the term “succession” to refer to the changes that happen in plant communities and ecosystems over time. The first community in a succession is called a pioneer community, while the long-lived community at the end of succession is called a climax community. Pioneer and successional plant communities are said to change over periods from 1 to 500 years. These changes—in plant numbers and the mix of species—are cumulative. Climax communities themselves change but over periods of time greater than about 500 years.2. According to paragraph 1, which of the following is NOT true of climax communities?○They occur at the end of a succession.○They last longer than any other type of community.○The numbers of plants in them and the mix of species do not change.○They remain stable for at least 500 years at a time.解析：C选项“do not change”和原文最后一句话“Climax communities themselves change but over periods of time greater than about 500 years.”矛盾。
例3：（TPO 10 Chinese Pottery）
Paragraph 3: The earliest ceramics were fired to earthenware temperatures, but as early as the fifteenth century B.C., high-temperature stonewares were being made with glazed surfaces. During the Six Dynasties period (AD 265-589), kilns in north China were producing high-fired ceramics of good quality. Whitewares produced in Hebei and Henan provinces from the seventh to the tenth centuries evolved into the highly prized porcelains of the Song dynasty (AD. 960-1279), long regarded as one of the high points in the history of China's ceramic industry. The tradition of religious sculpture extends over most historical periods but is less clearly delineated than that of stonewares or porcelains, for it embraces the old custom of earthenware burial ceramics with later religious images and architectural ornament. Ceramic products also include lead-glazed tomb models of the Han dynasty, three-color lead-glazed vessels and figures of the Tang dynasty, and Ming three-color temple ornaments, in which the motifs were outlined in a raised trail of slip—as well as the many burial ceramics produced in imitation of vessels made in materials of higher intrinsic value.5. Paragraph 3 supports all of the following concerning the history of the ceramic industry in China EXCEPT:○ The earliest high-fired ceramics were of poor quality.○ Ceramics produced during the Tang and Ming dynasties sometimes incorporated multiple colors.○ Earthenware ceramics were produced in China before stonewares were.○ The Song dynasty period was notable for the production of high quality porcelain ceramics.解析：A选项“poor quality”（not good quality）和原文“During the Six Dynasties period (AD 265-589), kilns in north China were producing high-fired ceramics of good quality.”矛盾。