The human can react to any situation, some of which he may never have imagined.（)

(41~45) Researchers have found that drugs used to treat human seizures can delay aging in worms by as much as 50 percent. The roundworms used for the study are similar to humans in their molecular makeup, raising the

possibility that the drugs could also extend the life span of humans。

第41题：“By finding a class of drugs that delays aging we have found a relationship between the function of the nervous system and aging that was not well understood, ” said Kerry Komfeld, a geneticist at the Washington University School of Medicine in St. Louis, Missouri. The findings are detailed this week in the journal Science。 The discovery came out of the thesis work by one of Komfeld’s graduate students, Kimberley Evason. About four years ago, Evason began exposing groups of the roundworm Caenorhabditis elegans to commercially available drugs to see if the drugs would delay aging or promote longevity。

A. But Komfeld said scientists will not know about the applicability of the drugs in humans until a similar study is done on humans. “What’s very encouraging is that these drugs were developed to treat humans, and they are well understood, because they’ve been used for a long time, ” he said。

B. Later the scientists discovered that two related anticonvulsant drugs also lengthened the lives of the worms-in the case of one drug, by almost 50 percent. “This was a big surprise to use, Komfeld said. ”“We didn’t think anticonvulsant drugs had any particular relationship to aging. That connection was completely unexpected. ”

C. Roundworms are a poor subject for experiments, because they are not like humans, even though their molecules are similar. For example, they have no bones, nor do they show emotions, making it difficult to know how exactly human subjects would react to these drugs in large quantities. However, using the worms allows experiments to be conducted quickly, because they do not live for long。

D. “Somehow the neural activity seems to regulate the aging of all of the body the skin, musculature, and reproductive tract, ” Kornfeld said. “Somehow the nervous system coordinates the progress of all these tissues, evidently, though the life stages. But we don’t know how it does that. ”

E. The discovery may also shed light on the little-understood aging process. Since the drugs act on the neuromuscular systems of both humans and worms, the findings hint at a link between neural activity and aging。

F. Unlike vertebrates, the worms are ideal subjects for the study of aging because of their short life spans, which last only a couple of weeks in a laboratory. The worm is well known in genetics, and the worm’s genome has been sequenced。

G. Use of this drug has been permitted by law since 1998 and wider use is now expected as a result of the studies. “We can clearly link this drug with human aging, but we still need to find proof, says Kornfeld optimistically. ”

ase. Since families have similar genes as well as similar environment, family diseases could be due to shared genetic influences, to shared environmental factors, or to both. For some years, the role of one's environmental factor commonly shared by families, namely, dietary salt, has been studied at Brookhaven National Laboratory. These studies suggest that chronic excess salt ingestion can lead to high blood pressure in man and animals. Some individuals, however, and some rats consume large amounts of salt without developing high blood pressure. No matter how strictly all environmental factors were controlled in these experiments, some salt - fed animals never develop hypertension whereas a few rapidly developed very severe hypertension followed by early death. These marked variations were interpreted to result from differences in genetic constitution.

By mating in successive generations only those animals that failed to develop hypertension from salt ingestion, a resistant strain (the" R" strain) has been evolved in which consumption of large quantities of salt fails to influence the blood pressure significantly. In contrast, by mating only animals that quickly develop hypertension from salt, a sensitive strain ("S" strain) has also been developed.

The availability of these two strains permits investigations not heretofore possible. They provide a plausible laboratory model on which to investigate some clinical aspects of the human proto - types of hypertension. More important, there might be the possibility of developing methods by which genetic susceptibility of human beings to high blood pressure can be defined without waiting for its appearance.

Which statement relates the main idea of this passage？

A．When salt is added to their diets, rats and men react in much the same way.

B．The near future will see a cure for high blood pressure.

C．Modem research has shown that high blood pressure is a result of salt in the diet.

D．A tendency toward high blood pressure may be a hereditary factor.

sease. Since families have similar genes as well as similar environments, familial diseases could be due to shared genetic influences, to shared environmental factors, or to both. For some years, the role of one environment factor commonly shared by families, namely dietary salt (i.e., sodium chloride), has been studied at Brookhaven National Laboratory. These studies suggest that long excess salt intake can lead to high blood pressure in man and animals. Some individuals, however, and some rats consume large amounts of salt without developing high blood pressure. No matter how strictly all environmental factors were controlled in these experiments, some salt-fed animals never developed hypertension whereas a few rapidly developed very severe hypertension followed by early death. These marked variations were interpreted to result from differences in genetic constitution.

By mating long successive generations of those animals that failed to develop hypertension from salt intake, a resistant strain (the " R" strain) has been evolved in which consumption of large quantities of salt fails to influence the blood pressure significantly. In contrast, by mating only animals that quickly develop hypertension from salt, sensitive strain (the "S" strain) has also been developed.

The availability of these two strains permits investigations possible. They provide a plausible laboratory model on which to investigate some clinical aspects of the human hypertension. More important, there might be the possibility of developing methods by which genetic susceptibility (敏感性) of human beings to high blood pressure can be defined without waiting for its appearance. Radioactive sodium 22 was an important "tool" in working out the characteristics of the sodium chloride metabolism.

The study of the effects of salt on high blood pressure was carried out_______.

A.as members of the same family tend to use similar amounts of salt

B.to explore the long-term use of a sodium based substance

C.because it was proven that salt caused high blood pressure

D.because of the availability of chemically pure salt and its derivatives

The main difference between "S" and "R" rats is their_______.A.need for sodium

B.rate of mating

C.type of blood

We can infer from the article that sodium 22 can be used to_______.A.control high blood pressure

B.cure high blood pressure caused by salt

C.tell the "S" rats from the "R" rats

D.determine what a sodium chloride metabolism is like

The most beneficial results of the research might be_______.A.development of diets free of salt

B.an early cure for high blood pressure

C.control of genetic agents that cause high blood pressure

D.the early identification of potential high blood pressure victims

Which of the statements best relates the main idea of this article？A.When salt is added rats and human beings react similarly.

B.The near future will see a cure for high blood pressure.

C.The medical field is desperately in need of research.

D.A tendency toward high blood pressure may be a hereditary factor.

请帮忙给出每个问题的正确答案和分析，谢谢！

t implications fox human aging as well. There are strong similarities on the molecular level between the proteins and genes that

A. But Komfeld said scientists will not know about the applicability of the drugs in humans until a similar study is done on humans. “What’s very encouraging is that these drugs were developed to treat humans, and they are well understood, because they’ve been used for a long time, ” he said。

B. Later the scientists discovered that two related anticonvulsant drugs also lengthened the lives of the worms-in the case of one drug, by almost 50 percent. “This was a big surprise to use, Komfeld said. ”“We didn’t think anticonvulsant drugs had any particular relationship to aging. That connection was completely unexpected. ”

C. Roundworms are a poor subject for experiments, because they are not like humans, even though their molecules are similar. For example, they have no bones, nor do they show emotions, making it difficult to know how exactly human subjects would react to these drugs in large quantities. However, using the worms allows experiments to be conducted quickly, because they do not live for long。

D. “Somehow the neural activity seems to regulate the aging of all of the body the skin, musculature, and reproductive tract, ” Kornfeld said. “Somehow the nervous system coordinates the progress of all these tissues, evidently, though the life stages. But we don’t know how it does that. ”

E. The discovery may also shed light on the little-understood aging process. Since the drugs act on the neuromuscular systems of both humans and worms, the findings hint at a link between neural activity and aging。

F. Unlike vertebrates, the worms are ideal subjects for the study of aging because of their short life spans, which last only a couple of weeks in a laboratory. The worm is well known in genetics, and the worm’s genome has been sequenced。

G. Use of this drug has been permitted by law since 1998 and wider use is now expected as a result of the studies. “We can clearly link this drug with human aging, but we still need to find proof, says Kornfeld optimistically. ”

ar function. Said Kornfeld: “The process of aging remains mysterious. ”

A. But Komfeld said scientists will not know about the applicability of the drugs in humans until a similar study is done on humans. “What’s very encouraging is that these drugs were developed to treat humans, and they are well understood, because they’ve been used for a long time, ” he said。

B. Later the scientists discovered that two related anticonvulsant drugs also lengthened the lives of the worms-in the case of one drug, by almost 50 percent. “This was a big surprise to use, Komfeld said. ”“We didn’t think anticonvulsant drugs had any particular relationship to aging. That connection was completely unexpected. ”

C. Roundworms are a poor subject for experiments, because they are not like humans, even though their molecules are similar. For example, they have no bones, nor do they show emotions, making it difficult to know how exactly human subjects would react to these drugs in large quantities. However, using the worms allows experiments to be conducted quickly, because they do not live for long。

D. “Somehow the neural activity seems to regulate the aging of all of the body the skin, musculature, and reproductive tract, ” Kornfeld said. “Somehow the nervous system coordinates the progress of all these tissues, evidently, though the life stages. But we don’t know how it does that. ”

E. The discovery may also shed light on the little-understood aging process. Since the drugs act on the neuromuscular systems of both humans and worms, the findings hint at a link between neural activity and aging。

F. Unlike vertebrates, the worms are ideal subjects for the study of aging because of their short life spans, which last only a couple of weeks in a laboratory. The worm is well known in genetics, and the worm’s genome has been sequenced。

G. Use of this drug has been permitted by law since 1998 and wider use is now expected as a result of the studies. “We can clearly link this drug with human aging, but we still need to find proof, says Kornfeld optimistically. ”

y they tested the anticonvulsant drug ethosuzimide. Researchers found that the drug extended the life span of roundworms from 16. 7 days to 19. 6 days, a 17 percent increase。

A. But Komfeld said scientists will not know about the applicability of the drugs in humans until a similar study is done on humans. “What’s very encouraging is that these drugs were developed to treat humans, and they are well understood, because they’ve been used for a long time, ” he said。

B. Later the scientists discovered that two related anticonvulsant drugs also lengthened the lives of the worms-in the case of one drug, by almost 50 percent. “This was a big surprise to use, Komfeld said. ”“We didn’t think anticonvulsant drugs had any particular relationship to aging. That connection was completely unexpected. ”

C. Roundworms are a poor subject for experiments, because they are not like humans, even though their molecules are similar. For example, they have no bones, nor do they show emotions, making it difficult to know how exactly human subjects would react to these drugs in large quantities. However, using the worms allows experiments to be conducted quickly, because they do not live for long。

D. “Somehow the neural activity seems to regulate the aging of all of the body the skin, musculature, and reproductive tract, ” Kornfeld said. “Somehow the nervous system coordinates the progress of all these tissues, evidently, though the life stages. But we don’t know how it does that. ”

E. The discovery may also shed light on the little-understood aging process. Since the drugs act on the neuromuscular systems of both humans and worms, the findings hint at a link between neural activity and aging。

F. Unlike vertebrates, the worms are ideal subjects for the study of aging because of their short life spans, which last only a couple of weeks in a laboratory. The worm is well known in genetics, and the worm’s genome has been sequenced。

G. Use of this drug has been permitted by law since 1998 and wider use is now expected as a result of the studies. “We can clearly link this drug with human aging, but we still need to find proof, says Kornfeld optimistically. ”

though it is no known precisely how the drug controls convulsions. There is no anecdotal evidence that it has had an anti-aglng effect in people. The next step, Komfeld says, is to test if the drugs have an anti-aging effect on animal like flies and mice。 Very little is known about the aging process. From genetic analysis, researchers have found that an in sulin-like signaling system regulates aging and longevity. A good diet can delay aging and extend a person life span. But scientists know virtually nothing about the effect of drugs on aging. “It’s a big void, ” Konfeld said。 In addition to delaying age-related degenerative changes, the drugs also increased neuromuscular activty, suggesting a link between the neuromuscular system and the aging process。

A. But Komfeld said scientists will not know about the applicability of the drugs in humans until a similar study is done on humans. “What’s very encouraging is that these drugs were developed to treat humans, and they are well understood, because they’ve been used for a long time, ” he said。

B. Later the scientists discovered that two related anticonvulsant drugs also lengthened the lives of the worms-in the case of one drug, by almost 50 percent. “This was a big surprise to use, Komfeld said. ”“We didn’t think anticonvulsant drugs had any particular relationship to aging. That connection was completely unexpected. ”

C. Roundworms are a poor subject for experiments, because they are not like humans, even though their molecules are similar. For example, they have no bones, nor do they show emotions, making it difficult to know how exactly human subjects would react to these drugs in large quantities. However, using the worms allows experiments to be conducted quickly, because they do not live for long。

D. “Somehow the neural activity seems to regulate the aging of all of the body the skin, musculature, and reproductive tract, ” Kornfeld said. “Somehow the nervous system coordinates the progress of all these tissues, evidently, though the life stages. But we don’t know how it does that. ”

E. The discovery may also shed light on the little-understood aging process. Since the drugs act on the neuromuscular systems of both humans and worms, the findings hint at a link between neural activity and aging。

F. Unlike vertebrates, the worms are ideal subjects for the study of aging because of their short life spans, which last only a couple of weeks in a laboratory. The worm is well known in genetics, and the worm’s genome has been sequenced。

G. Use of this drug has been permitted by law since 1998 and wider use is now expected as a result of the studies. “We can clearly link this drug with human aging, but we still need to find proof, says Kornfeld optimistically. ”

A．finding excuses helps in learning

B．to react negatively can be harmful

C．hard work is the key to success

D．making use of the computer is important

Which one is not true according to the video？

A.High-power alpha males in primate hierarchies have high testosterone and low cortisol.

B.Powerful and effective leaders have high testosterone and low cortisol.

C.Power has nothing about how you react to stress.

D.Body can shape the mind, at least at the facial level.