托福阅读理解真题精选篇

若水1147由分享时间：2020-08-30 06:09:42

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新托福阅读背景知识精选5篇

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为了让大家更好的准备托福考试，小编给大家整理一些托福阅读真题，下面小编就和大家分享，来欣赏一下吧。

托福阅读真题1

The smooth operation of an ant colony depends on ten to twenty different signals, most of which are pheromones (chemical signals triggering behavioral responses). It is estimated that red fire ants employ at least twelve different chemical signals. The simplest of these is the carbon dioxide from the respiration of an ant cluster, a chemical that acts as a pheromone to promote aggregation. Workers move toward a source of carbon dioxide, resulting in solitary ants moving to join a group. At the other extreme, the most complex of the fire ants' signals is probably colony odor, by which the workers of a particular colony or nest identify another worker as local or foreign. Each ant nest has its own odor as a result of its location, history, and local food supply. The resident ants pick up this odor on their bodies, so that ants of the same species, but from different nests, have different colony odors. This allows ants to identify intruders and maintain colony integrity.

Fire ants also make use of an alarm pheromone to alert workers to an emergency, and their scouts lay down a trail pheromone as a guide during mass migrations. A fire ant queen emits a chemical signal that identifies her to the colony's workers. They respond by scurrying to gather around her. The decomposing corpse of a dead ant also generates a signal, to which workers respond by eliminating the corpse from the nest.

Ants provide examples of both public (accessible to other species) and private messages. One of their most important private messages concerns food, for a food source is worth keeping secret. Each species marks its trails with signals that are meaningless to others, so that an ant crossing a trail left by another ant species typically notices nothing. On the other hand, a secret signal to mark a dead body is unnecessary. Many kinds of ants perceive a natural decomposition product of dead insects as a signal to remove a corpse. If an outsider recognizes this message and moves the body, no harm is done.

1. What aspect of ants does the passage mainly discuss?

(A) The relationship between the queen and the worker ants

(B) Ways in which ants use chemical signals

(D) The importance of respiration in the production of ant pheromones

2. The phrase smooth operation in line 1 is closest in meaning to

(A) daily activity

(B) effective functioning

(D) permanent location

3. According to the passage , carbon dioxide serves which of the following functions for fire ants?

(A) It protects the queen.

(B) It attracts other ant species.

(D) It encourages the ants to gather together.

4. The word cluster in line 4 is closest in meaning to

(A) organ

(B) activity

(D) cycle

5. According to the passage , each nest has a distinct odor that allows its inhabitants to

(A) find the location of the nest in the dark

(B) distinguish worker ants from other ants

(D) signal other inhabitants when foreign ants attack

6. The word alert in line 13 is closest in meaning to

(A) allow

(B) transport

(D) provide

7. What is the role of pheromones in the mass migrations of ants?

(A) Pheromones are used to create a trail that directs the ants during migrations.

(B) Pheromones signal the ants that the nest has been invaded and must be abandoned.

(D) Pheromones enable scouts to identify suitable areas for establishing a new nest.

8. The word scurrying in line 16 is closest in meaning to

(A) agreeing

(B) appearing

(D) rushing

9. The word others in line 21 refers to

(A) private messages

(B) species

(D) signals

10. Why does the author mention dead insects in line 23?

(A) To compare the social behaviors of ants with those of other insects

(B) To emphasize the dangers that all insects encounter

(D) To indicate a behavior that is common among various kinds of ants

11. Which of the following terms is defined in the passage ?

(A) pheromones (line 2)

(B) colony integrity (lines 12)

(D) private messages (lines 18-19)

PASSAGE 86 BBDCC CADBD A

托福阅读真题2

Because the low latitudes of the Earth, the areas near the equator, receive more heat than the latitudes near the poles, and because the nature of heat is to expand and move, heat is transported from the tropics to the middle and high latitudes. Some of this heat is moved by winds and some by ocean currents, and some gets stored in the atmosphere in the form of latent heat. The term latent heat refers to the energy that has to be used to convert liquid water to water vapor. We know that if we warm a pan of water on a stove, it will evaporate, or turn into vapor, faster than if it is allowed to sit at room temperature. We also know that if we hang wet clothes outside in the summertime they will dry faster than in winter, when temperatures are colder. The energy used in both cases to change liquid water to water vapor is supplied by heat — supplied by the stove in the first case and by the Sun in the latter case. This energy is not lost. It is stored in water vapor in the atmosphere as latent heat. Eventually, the water stored as vapor in the atmosphere will condense to liquid again, and the energy will be released to the atmosphere.

In the atmosphere, a large portion of the Sun's incoming energy is used to evaporate water, primarily in the tropical oceans. Scientists have tried to quantify this proportion of the Sun's energy. By analyzing temperature, water vapor, and wind data around the globe, they have estimated the quantity to be about 90 watts per square meter, or nearly 30 percent of the Sun's energy. Once this latent heat is stored within the atmosphere, it can be transported, primarily to higher latitudes, by prevailing, large-scale winds. Or it can be transported vertically to higher levels in the atmosphere, where it forms clouds and subsequent storms, which then release the energy back to the atmosphere.

1. The passage mainly discusses how heat

(A) is transformed and transported in the Earth's atmosphere

(B) is transported by ocean currents

(D) moves about the Earth's equator

2. The passage mentions that the tropics differ from the Earth's polar regions in which of the

following ways?

(A) The height of cloud formation in the atmosphere.

(B) The amount of heat they receive from the Sun.

(D) The strength of their oceanic currents.

3. The word convert in line 6 is closest in meaning to

(A) mix

(B) change

(D) reduce

4. Why does the author mention the stove in line 10?

(A) To describe the heat of the Sun.

(B) To illustrate how water vapor is stored.

(D) To give an example of a heat source.

5. According to the passage , most ocean water evaporation occurs especially

(A) around the higher latitudes

(B) in the tropics

(D) because of strong ocean currents

6. According to the passage , 30 percent of the Sun's incoming energy

(A) is stored in clouds in the lower latitudes

(B) is transported by ocean currents

(D) gets stored as latent heat

7. The word it in line 18 refers to

(A) square meter

(B) the Sun's energy

(D) the atmosphere

8. The word primarily in the line 19 is closest in meaning to

(A) chiefly

(B) originally

(D) clearly

9. The word prevailing in line 19 is closest in meaning to

(A) essential

(B) dominant

(D) closest

10. All of the following words are defined in the passage EXCEPT

(A) low latitudes(line 1)

(B) latent heat (line 5)

(D) atmosphere (line 14)

PASSAGE 87 ABBDB DCABD

托福阅读真题3

Generally, in order to be preserved in the fossil record, organisms must possess hard body parts such as shells or bones. Soft, fleshy structures are quickly destroyed by predators or decayed by bacteria. Even hard parts left on the surface for a certain length of time will be destroyed. Therefore, organisms must be buried rapidly to escape destruction by the elements and to be protected against agents of weathering and erosion. Marine organisms thus are better candidates for fossilization than those living on the land because the ocean is typically the site of sedimentation, whereas the land is largely the site of erosion.

The beds of ancient lakes were also excellent sites for rapid burial of skeletal remains of freshwater organisms and skeletons of other animals, including those of early humans. Ancient swamps were particularly plentiful with prolific growths of vegetation, which fossilized in abundance. Many animals became trapped in bogs overgrown by vegetation. The environment of the swamps kept bacterial decay to a minimum, which greatly aided in the preservation of plants and animals. The rapidly accumulating sediments in flood plains, deltas, and stream channels buried freshwater organisms, along with other plants and animals that happened to fall into the water.

(A) erosion is less destructive than sedimentation.

(B) fossils are most common in areas subject to erosion.

(D) few organisms live in areas that experience extensive erosion.

5. According to the passage , why were the remains of organisms trapped in swamps better

preserved for the fossil record than those that were not?

(A) The swamp environment reduced the amount of bacterial decay.

(B) Swamp waters contained higher amounts of materials such as calcium carbonate.

(D) Swamp vegetation accelerated the decomposition of organisms.

6. The word aided in line 13 is closest in meaning to

(A) reversed

(B) helped

(D) counted

7. It can be inferred that flood plains, deltas, and stream channels (lines 14 - 15) are similar in

which of the following ways?

(A) Animals rather than plants have been preserved at such locations.

(B) Such locations are likely to be rich sources of fossils.

(D) Rapid sedimentation in such locations makes it difficult to locate fossils.

8. What is the author's main point in paragraph 3?

(A) Weathering makes it impossible to identify many fossils.

(B) Many fossils have been buried forever under the soil.

(D) It is easier to find the remains of plants than animals.

9. Why does the author mention aragonite in line 27

(A) To explain why fossils are rare

(B) To compare aragonite fossils and calcite fossils

(D) To illustrate the kinds of inorganic hard parts that can form fossils

PASSAGE 88 ADBCA BBCD

Only a small fraction of all the organisms that have ever lived are preserved as fossils. Normally, the remains of a plant or animal are completely destroyed through predation and decay. Although it seems that fossilization is common for some organisms, for others it is almost impossible. For the most part, the remains of organisms are recycled in the earth, which is fortunate because otherwise soil and water would soon become depleted of essential nutrients. Also, most of the fossils exposed on Earth's surface are destroyed by weathering processes. This makes for an incomplete fossil record with poor or no representation of certain species.

The best fossils are those composed of unaltered remains. Generally, it is the inorganic hard parts, composed mostly of calcium carbonate, that form the vast majority of unaltered fossils. Calcite and aragonite also contributed to a substantial number of fossils of certain organisms.

1. According to the passage , an organism without hard body parts

(A) is not likely to appear in the fossil record

(B) is not heavy enough to sink below the surface

(D) takes a long time to decay

2. The word agents in line 5 is closest in meaning to

(A) dangers

(B) examples

(D) causes

3. Why are marine organisms good candidates for fossilization?

(A) They have more fleshy structures than land organisms.

(B) It is likely that they will be buried rapidly.

(D) It takes longer for them to be preserved.