GMAT - 语文部分（Verbal）

不定项选择题

The number of people diagnosed as having a certain intestinal disease has dropped significantly in a rural county this year, as compared to last year, health officials attribute this decrease entirely to improved sanitary conditions at water-treatment plants, which made for cleaner water this year and thus reduced the incidence of the disease. Which of the following, if true, would most seriously weaken the health officials explanation for the lower incidence of the disease？

A. Many new water-treatment plants have been built in the last five years in the rural county.
Bottled spring water has not been consumed in significantly different quantities by people diagnosed as having the intestinal disease, as compared to people who did not contract the disease.
C. Because of a new diagnostic technique, many people who until this year would have been diagnosed as having the intestinal disease are now correctly diagnosed as suffering from intestinal ulcers.
D. Because of medical advances this year, far fewer people who contract the intestinal disease will develop severe cases of the disease.
E. The water in the rural county was brought up to the sanitary standards of the water in neighboring counties ten years ago.

查看答案

单选题

Scientists have found that inserting genes from a plant virus into the genes of a plant susceptible to that virus increases the plant s resistance to the virus. Because viral diseases account for a significant proportion of crop losses, such genetic alterations, even if carried out on only a modest scale, will significantly reduce crop losses. Each of the following, if true, strengthens the conclusion above EXCEPT:

A. In areas where two successive crops are raised per year, protecting the first crop from a virus will generally protect the second crop from that virus as well.
By repeatedly attacking plants that are genetically altered to become virus-resistant, the virus often becomes less lethal to plants that are not genetically altered in that way.
C. Plants that are genetically altered to become virus-resistant often pass virus-resistant genes on to their offspring.
D. Plants that arc made genetically resistant to one kind of virus often acquire resistance to related viral strains as well.
E. Plants that are made genetically resistant to one kind of virus are then more susceptible to infection by unrelated viruses.

查看答案

不定项选择题

The sensation of pain cannot accurately be described as "located" at the point of an injury, or, for that matter, in any one place in the nerves or brain. Rather, pain signals—and pain relief—are delivered through a highly complex interacting circuitry. When a cell is injured, a rush of prostaglandin s sensitizes nerve endings at the injury. Prostaglandins are chemicals produced in and released from virtually all mammalian cells when they are injured: these are the only pain signals that do not originate in the nervous sys- tern. Aspirin and other similar drugs(such as indomethacin and ibuprofen)keep prostaglandins from being made by interfering with an enzyme known as prostaglandin synthetase, or cyclooxy- genase. The drugs effectiveness against pain is proportional to their success in blocking this enzyme at the site of injury. From nerve endings at the injury, pain signals move to nerves feeding into the spinal cord. The long, tubular membranes of nerve cells carry electrical impulses. When electrical impulses get to the spinal cord, a pain-signaling chemical known as substance P is released there. Substance P then excites nearby neurons to send impulses to the brain. Local anesthetics such as novo-caine and xylocaine work by blocking the electrical transmission along nerves in a particular area. They inhibit the flow of sodium ions through the membranes, making the nerves electrically quiescent; thus no pain signals are sent to the spinal cord or to the brain. Recent discoveries in the study of pain have involved the brain itself—the supervising organ that notices pain signals and that sends messages down to the spinal cord to regulate incoming pain traffic. Endorphins-—the brain s own morphine—are a class of small peptides that help to block pain signals within the brain itself. The presence of endor- phins may also help to explain differences in response to pain signals, since individuals seem to differ in their ability to produce endorphins. It now appears that a number of techniques for blocking chronic pain—such as acupuncture and electrical stimulation of the central brain stem—involve the release of endorphins in the brain and spinal cord.<br>The passage is primarily concerned with

A. analyzing ways that enzymes and other chemicals influence how the body feels pain.
B. describing the presence of endorphins in the brain and discussing ways the body blocks pain within the brain itself.
C. describing how pain signals are conveyed in the body and discussing ways in which the pain signals can be blocked.
D. demonstrating that pain can be influenced by acupuncture and electrical stimulation of the central brain stem.
E. differentiating the kinds of pain that occur at different points in the body" s nervous system.

查看答案

不定项选择题

It can be inferred from the passage that one problem associated with the production of huge lots of cars is which of the following？

A. The need to manufacture flexible machinery and equipment.
B. The need to store extra components not required for immediate use.
C. The need for expensive training programs for workers, which emphasize the development of facility in several production jobs.
D. The need to alter conventional mass-production processes.
E. The need to increase the investment per vehicle in order to achieve high productivity levels.

查看答案

不定项选择题

With which of the following predictive statement regarding Japanese automakers would the author most likely agree？

A. The efficiency levels of the Japanese automakers will decline if they become less flexible in their approach to production.
B. Japanese automakers productivity levels double during the late 1990"s.
C. United States automakers will originate net production processes before Japanese automakers do.
D. Japanese automakers will hire fewer workers than will United States automakers because each worker is required to perform. several jobs.
E. Japanese automakers will spend less on equipment repairs than will United States automakers because Japanese equipment can be easily altered.

查看答案

不定项选择题

Until recently most astronomers believed that the space between the galaxies in our universe was a near perfect vacuum. This orthodox view of the universe is now being challenged by astronomers who believe that a heavy "rain" of gas is falling into many galaxies from the supposedly empty space around them. The gas apparently con- denses into a collection of small stars, each a little larger than the planet Jupiter. These stars vastly outnumber the other stars in a given galaxy. The amount of " intergalactic rainfall" into some of these galaxies has been enough to double their mass in the time since they formed. Scientists have begun to suspect that this intergalactic gas is probably a mixture of gases left over from the "big bang" when the galaxies were formed and gas was forced out of galaxies by supernova explosions. It is well known that when gas is cooled at a constant pressure its volume decreases. Thus, the physicist Fabian reasoned that as intergalactic gas cools, the cooler gas shrinks inward toward the center of the galaxy. Meanwhile its place is taken by hotter intergalactic gas from farther out on the edge of the galaxy, which cools as it is compressed and flows into the galaxy. The net result is a continuous flow of gas, starting as hot gases in inter galactic space and ending as a drizzle of cool gas called a "cooling flow," falling into the central galaxy. A fairly heretical idea in the 1970s, the cooling-flow theory gained sup- port when Fabian observed a cluster of galaxies in the constellation Perseus and found the central galaxy, NGC 1275, to be a strange-looking object with irregular, thin strands of gas radiating from it. According to previous speculation, these strands were gases that had been blown out by an explosion in the galaxy. Fabian, however, disagreed. Because the strands of gas radiating from NGC 1275 are visible in optical photographs, Fabian suggested that such strands consisted not of gas blown out of the galaxy but of cooling flows of gas streaming inward. He noted that the wavelengths of the radiation emitted by a gas would changes as the gas cooled, so that as the gas flowed into the galaxy and became cooler, it would emit not x-rays, but visible light, like that which was captured in the photographs. Fabians hypothesis was supported by Canizares determination in 1982 that most of the gas in the Perseus cluster was at a temperature of 80 mil lion degrees Kelvin, whereas the gas immediately surrounding NGC 1275(the subject of the photographs)was at one-tenth this temperature.<br>The primary purpose of the passage is to

A. illustrate a hypothesis about the origin of galaxies.
B. provide evidence to dispute an accepted theory about the evolution of galaxies.
C. summarize the state of and prospects for research in intergalactic astronomy.
D. report new data on the origins of intergalactic gas.
E. reconcile opposing views on the formation of intergalactic gas.

查看答案

单选题

Until recently experts believed that environment, not genetics, largely determines human personality. A new study, however, has shown that there is more similarity in personality between identical twins raised together than between non-identical twins raised together. The study concluded that genetics, therefore, does play an important role in determining personality. Which of the following, if found to be true, would cast the most doubt on the studys conclusion？

A. Identical twins raised separately in different adoptive families are usually more similar in personality than are nonidentical twins raised separately in different adoptive families.
B. No matter how twins behave, parents treat identical twins in ways that tend to elicit similar personality traits but do not treat nonidentical twins in such ways.
C. Parents of both identical and nonidentical twins have long claimed that their children, from early infanthood, had definite and well-established personality traits.
D. Birth parents and their identical twin children tend to become more similar to each other in personality over time, but adoptive parents and their identical twin children do not.
E. Neither identical nor nonidentical twins are likely to display drastic changes in their individual personalities as they grow up.

查看答案

不定项选择题

Scientists have rediscovered certain food crops, once commonly cultivated in the New World, which contain more protein per pound than do current staple food crops such as rice and wheat. Scientists claim that cultivation of these crops could greatly benefit densely populated countries that have low per-person caloric intake and inadequate source of protein. Which of the following, if true, casts the most serious doubt on the claim made above？

A. The average yield per acre of the rediscovered crops is substantially less than that of the current staple food crops.
B. Many important food crops, such as tomato, originated in the New World.
C. Wheat yields more protein per pound than does rice.
D. The rediscovered crops have more caloric per pound than do current, staple food crops.
E. As few as 20 different food crops provide the bulk of the planet"s food supply.

查看答案

单选题

Government department head: We already have a code of ethics that companies doing business

A. The code of ethics applies only to companies that do business with the department.
B. The code of ethics was instituted only after it was discovered that several companies had committed serious violations of ethics in their business with the department.
C. A government investigation found that most of the companies that agreed to abide by the department" s code of ethics are not complying with it.
D. A survey of major companies found that several companies stopped doing business with the department because they did not want to agree to abide by the code of ethics.
E. A study of codes of ethics for companies found that the codes are most effective when the top executives of companies that agree to abide by them are fully committed to following them.

查看答案

不定项选择题

A greater number of newspapers are sold in Town S than in Town T. Therefore, the citizens

A. Town S has a larger population than Town T.
B. Most citizens of Town T work in Town S and buy their newspapers there.
C. The average citizen of Town S spends less time reading newspapers than does the average citizen of Town T.
D. A weekly newspaper restricted to the coverage of local events is published in Town S.
E. The average newsstand price of newspapers sold in Town S is lower than the average price of newspapers sold in Town T.

查看答案