A Cat’s Sense of Smell
题目：
Cats have sensitive noses that they use for a variety of purposes, including finding mates and identifying the territory of other cats. Given their reliance on smell, it seems remarkable that the first scientific account of cats using scent in hunting was published in 2010. This study showed that cats do indeed locate prey using the scent marks of prey. Many of the rodents that cats hunt, especially mice, communicate with one another using scent signals carried in their urine. As mammals, cats and mice have noses that work in much the same way, so it is highly unlikely that mice can disguise their scent marks so that cats cannot detect them. Australian biologists proved this by collecting sand from mouse cages and placing it on the ground on the sides of roads. Almost all these patches of sand were visited by predators-mostly foxes, but tracks of wild cats were also apparent-while clean sand was not. The collected data from the experiment did not show how far away the cats had traveled from, but it is possible that significant distances were involved-that is, the cats probably navigated upwind toward the odor sources, rather than only investigating the patches of sand because they looked unusual. We know that many dogs prefer to hunt using their noses and can detect and then locate sources of odor from manv meters awav. While cats prefer to use vision when hunting in daylight, they probably switch to using their sense of smell when hunting at night, when sight, even their sensitive night vision, is likely inadequate for hunting.
Finding prey from the odors it produces can be difficult. Scent marks rarely indicate the current position of the animal that left them, only where it was when it made the mark, perhaps hours earlier. In the sand experiment, the urine samples continued to attract cats for at least a couple of days. It’s possible that cats, as sit-and-wait hunters, use the scent marks to see whether they will attract other members of the same species that made them. Mice use urine marks to signal to other mice, and the marks contain a great deal of useful information about the mouse that produced them. Thus, the animal leaving the scent mark doesn’t put itself at risk so much as other members of the same species that show up to examine the mark.
Moreover, odors spread out from their sources in ways that are not predictable. We know intuitively that light travels in straight lines but not around obstacles, and that sound travels in all directions, including around obstacles. However, because we rely so little on odor to give us directional information, it’s not immediately obvious what problems animals face when determining where an odor is emanating from. Of course, odors outdoors are carried by the air-downwind, not upwind-but air movements close to the ground, where cats operate, are usually highly complex. While the wind may be blowing in a consistent direction a few yards above the ground, friction caused by its contact with the ground and especially with vegetation causes it to break up into eddies (fast-moving circles of air) of various sizes. These carry “pockets” of odor away from the source, so that a cat somewhere downwind of a mouse’s nest will get intermittent bursts of mouse smell.
Tracing these bursts to their source, especially in thick vegetation, is likely to require diligent searching and possibly some backtracking. Once a cat has located a source of mouse odor, it is potentially able to use the fact that odors don’t travel upwind to position itself downwind of the odor source so its own smell can’t be detected by the mouse and then wait for mice to turn up. While sit-and-wait is a well-documented hunting method used by cats, we do not know whether cats routinely prefer patrolling the downwind side of, for example, hedgerows (rows of plants) to avoid their own scent betraying their presence. However, it seems likely that a predator as smart as a cat could quickly learn this tactic, even if it is not instinctive.
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Cats have sensitive noses that they use for a variety of purposes, including finding mates and identifying the territory of other cats. Given their reliance on smell, it seems remarkable that the first scientific account of cats using scent in hunting was published in 2010. This study showed that cats do indeed locate prey using the scent marks of prey. Many of the rodents that cats hunt, especially mice, communicate with one another using scent signals carried in their urine. As mammals, cats and mice have noses that work in much the same way, so it is highly unlikely that mice can disguise their scent marks so that cats cannot detect them. Australian biologists proved this by collecting sand from mouse cages and placing it on the ground on the sides of roads. Almost all these patches of sand were visited by predators-mostly foxes, but tracks of wild cats were also apparent-while clean sand was not. The collected data from the experiment did not show how far away the cats had traveled from, but it is possible that significant distances were involved-that is, the cats probably navigated upwind toward the odor sources, rather than only investigating the patches of sand because they looked unusual. We know that many dogs prefer to hunt using their noses and can detect and then locate sources of odor from manv meters awav. While cats prefer to use vision when hunting in daylight, they probably switch to using their sense of smell when hunting at night, when sight, even their sensitive night vision, is likely inadequate for hunting.
The phrase “reliance on” in the passage is closest in meaning to
Vocabulary Questions词汇题
Adependence on
Bemphasis on
Cpreference for
Dsensitivity of
2
Cats have sensitive noses that they use for a variety of purposes, including finding mates and identifying the territory of other cats. Given their reliance on smell, it seems remarkable that the first scientific account of cats using scent in hunting was published in 2010. This study showed that cats do indeed locate prey using the scent marks of prey. Many of the rodents that cats hunt, especially mice, communicate with one another using scent signals carried in their urine. As mammals, cats and mice have noses that work in much the same way, so it is highly unlikely that mice can disguise their scent marks so that cats cannot detect them. Australian biologists proved this by collecting sand from mouse cages and placing it on the ground on the sides of roads. Almost all these patches of sand were visited by predators-mostly foxes, but tracks of wild cats were also apparent-while clean sand was not. The collected data from the experiment did not show how far away the cats had traveled from, but it is possible that significant distances were involved-that is, the cats probably navigated upwind toward the odor sources, rather than only investigating the patches of sand because they looked unusual. We know that many dogs prefer to hunt using their noses and can detect and then locate sources of odor from manv meters awav. While cats prefer to use vision when hunting in daylight, they probably switch to using their sense of smell when hunting at night, when sight, even their sensitive night vision, is likely inadequate for hunting.
The experiment described in paragraph 1 established which of the following about cats?
Factual Information Questions事实信息题
AThey hunt rodents more commonly than other prey.
BThey sometimes hunt by using the scent marks of their prey
CThey communicate with one another by using scent signals.
DThey are better at detecting the scent signals of mice than of other prey.
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Cats have sensitive noses that they use for a variety of purposes, including finding mates and identifying the territory of other cats. Given their reliance on smell, it seems remarkable that the first scientific account of cats using scent in hunting was published in 2010. This study showed that cats do indeed locate prey using the scent marks of prey. Many of the rodents that cats hunt, especially mice, communicate with one another using scent signals carried in their urine. As mammals, cats and mice have noses that work in much the same way, so it is highly unlikely that mice can disguise their scent marks so that cats cannot detect them. Australian biologists proved this by collecting sand from mouse cages and placing it on the ground on the sides of roads. Almost all these patches of sand were visited by predators-mostly foxes, but tracks of wild cats were also apparent-while clean sand was not. The collected data from the experiment did not show how far away the cats had traveled from, but it is possible that significant distances were involved-that is, the cats probably navigated upwind toward the odor sources, rather than only investigating the patches of sand because they looked unusual. We know that many dogs prefer to hunt using their noses and can detect and then locate sources of odor from manv meters awav. While cats prefer to use vision when hunting in daylight, they probably switch to using their sense of smell when hunting at night, when sight, even their sensitive night vision, is likely inadequate for hunting.
According to paragraph 1, cats are able to detect the scent signals of mice because
Factual Information Questions事实信息题
Acats have been predators of mice for a long time
Bthe scent marks of cats and mice are similar
Ccats and mice have similar systems for detecting odors
Dboth cats and mice carry scent signals in their urine
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Cats have sensitive noses that they use for a variety of purposes, including finding mates and identifying the territory of other cats. Given their reliance on smell, it seems remarkable that the first scientific account of cats using scent in hunting was published in 2010. This study showed that cats do indeed locate prey using the scent marks of prey. Many of the rodents that cats hunt, especially mice, communicate with one another using scent signals carried in their urine. As mammals, cats and mice have noses that work in much the same way, so it is highly unlikely that mice can disguise their scent marks so that cats cannot detect them. Australian biologists proved this by collecting sand from mouse cages and placing it on the ground on the sides of roads. Almost all these patches of sand were visited by predators-mostly foxes, but tracks of wild cats were also apparent-while clean sand was not. The collected data from the experiment did not show how far away the cats had traveled from, but it is possible that significant distances were involved-that is, the cats probably navigated upwind toward the odor sources, rather than only investigating the patches of sand because they looked unusual. We know that many dogs prefer to hunt using their noses and can detect and then locate sources of odor from manv meters awav. While cats prefer to use vision when hunting in daylight, they probably switch to using their sense of smell when hunting at night, when sight, even their sensitive night vision, is likely inadequate for hunting.
According to paragraph 1, cats differ from many dogs in which of the following ways?
Factual Information Questions事实信息题
ACats prefer hunting at night.
BThe eyesight of cats becomes weaker at night.
CCats usually navigate upwind toward odor sources.
DCats depend mainly on eyesight to hunt in good light.
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Finding prey from the odors it produces can be difficult. Scent marks rarely indicate the current position of the animal that left them, only where it was when it made the mark, perhaps hours earlier. In the sand experiment, the urine samples continued to attract cats for at least a couple of days. It’s possible that cats, as sit-and-wait hunters, use the scent marks to see whether they will attract other members of the same species that made them. Mice use urine marks to signal to other mice, and the marks contain a great deal of useful information about the mouse that produced them. Thus, the animal leaving the scent mark doesn’t put itself at risk so much as other members of the same species that show up to examine the mark.
According to paragraph 2, all of the following are true of the scent marks left by mice EXCEPT:
Negative Factual Information Questions否定事实信息题
AThey remain detectable to cats for some time after they have been made.
BThey are used by mice mainly to determine how recently other mice have visited an area
CThey reveal details about the individual animals making them
DThey are less likely to endanger the mouse that made them than other mice that visit them.
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Finding prey from the odors it produces can be difficult. Scent marks rarely indicate the current position of the animal that left them, only where it was when it made the mark, perhaps hours earlier. In the sand experiment, the urine samples continued to attract cats for at least a couple of days. It’s possible that cats, as sit-and-wait hunters, use the scent marks to see whether they will attract other members of the same species that made them. Mice use urine marks to signal to other mice, and the marks contain a great deal of useful information about the mouse that produced them. Thus, the animal leaving the scent mark doesn’t put itself at risk so much as other members of the same species that show up to examine the mark.
Moreover, odors spread out from their sources in ways that are not predictable. We know intuitively that light travels in straight lines but not around obstacles, and that sound travels in all directions, including around obstacles. However, because we rely so little on odor to give us directional information, it’s not immediately obvious what problems animals face when determining where an odor is emanating from. Of course, odors outdoors are carried by the air-downwind, not upwind-but air movements close to the ground, where cats operate, are usually highly complex. While the wind may be blowing in a consistent direction a few yards above the ground, friction caused by its contact with the ground and especially with vegetation causes it to break up into eddies (fast-moving circles of air) of various sizes. These carry “pockets” of odor away from the source, so that a cat somewhere downwind of a mouse’s nest will get intermittent bursts of mouse smell.
Which of the following best describes the relationship of paragraph 3 to paragraph 2?
Rhetorical Purpose Questions修辞目的题
AParagraph 3 identifies some of the useful information mentioned in paragraph 2 that scent marks provide
BParagraph 3 discusses a second factor that contributes to the difficulty identified in paragraph 2 of using odor to find prey.
CParagraph 3 explains how cats avoid the problem identified in paragraph 2 of scent marks that are several days old.
DParagraph 3 provides support for the claim in paragraph 2 about the risks related to scent marks.
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Moreover, odors spread out from their sources in ways that are not predictable. We know intuitively that light travels in straight lines but not around obstacles, and that sound travels in all directions, including around obstacles. However, because we rely so little on odor to give us directional information, it’s not immediately obvious what problems animals face when determining where an odor is emanating from. Of course, odors outdoors are carried by the air-downwind, not upwind-but air movements close to the ground, where cats operate, are usually highly complex. While the wind may be blowing in a consistent direction a few yards above the ground, friction caused by its contact with the ground and especially with vegetation causes it to break up into eddies (fast-moving circles of air) of various sizes. These carry “pockets” of odor away from the source, so that a cat somewhere downwind of a mouse’s nest will get intermittent bursts of mouse smell.
Which of the following can be inferred from paragraph 3 about humans and their senses?
Inference Questions推理题
AHumans are better than other animals at obtaining directional information when obstacles are present.
BHumans are better at determining direction from sight and sound than from odor.
CHumans are better at detecting odors that originate close to the ground than odors that originate higher up
DHumans are better at detecting outdoor odors than indoor odors
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Tracing these bursts to their source, especially in thick vegetation, is likely to require diligent searching and possibly some backtracking. Once a cat has located a source of mouse odor, it is potentially able to use the fact that odors don’t travel upwind to position itself downwind of the odor source so its own smell can’t be detected by the mouse and then wait for mice to turn up. While sit-and-wait is a well-documented hunting method used by cats, we do not know whether cats routinely prefer patrolling the downwind side of, for example, hedgerows (rows of plants) to avoid their own scent betraying their presence. However, it seems likely that a predator as smart as a cat could quickly learn this tactic, even if it is not instinctive.
The word “diligent” in the passage is closest in meaning to
Vocabulary Questions词汇题
Athorough
Bdifficult
Cappropriate
Defficient
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Finding prey from the odors it produces can be difficult. [■] Scent marks rarely indicate the current position of the animal that left them, only where it was when it made the mark, perhaps hours earlier. In the sand experiment, the urine samples continued to attract cats for at least a couple of days. [■] It’s possible that cats, as sit-and-wait hunters, use the scent marks to see whether they will attract other members of the same species that made them. [■] Mice use urine marks to signal to other mice, and the marks contain a great deal of useful information about the mouse that produced them. [■] Thus, the animal leaving the scent mark doesn’t put itself at risk so much as other members of the same species that show up to examine the mark.
Look at the four squares [■] that indicate where the following sentence could be added to the passage
This finding raises the issue of whether cats benefit from visiting a scent mark after the prey animal that made it has left.
Insert Text Questions句子插入题
Where would the sentence best fit？Click on a square sentence to the passage.
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Cats use their sense of smell for a variety of purposes, including hunting.
Prose Summary Questions概要小结题
Select 3 answers
AAlthough cats prefer hunting during the day, a 2010 study showed that cats sometimes travel long distances at night to find prey, using only their sense of smell to guide them
BCats sometimes hunt by locating a prey animal’s scent signal and then waiting for another member of the prey animal’s species to investigate the scent signal.
CUsing scent for hunting is challenging in part because air currents near the ground can make it difficult to determine the direction from which a scent is coming.
DIt has been shown that cats can detect scent signals left by prey animals and that cats are more likely to visit sites containing the scent signals of prey than sites without them.
EFrom a scent mark left by a prey animal, a cat can determine about how long ago the scent mark was made and thus how far away the prey animal making it is likely to be.
FWhen cats can detect only pockets of odor, they change their hunting strategy and begin searching vegetation such as hedgerows to find prey
