(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. ”
第1题：
In July 1989, Dr.Fox and a team of scientists achieved a major scientific breakthrough.Fox discovered the gene (基因) that causes cystic fibrosis (膀胱纤维症) (CF).Many geneticists consider it 's one of the most significantdiscoveries in human genetics.Theresults of Fox work have helped scientists developtests that identify carriers of the CFgene.They hope his research could cure CF.a testhas been developed to identify peoplerrying the cystic fibrosis gene.The test isbased on knowing where the gene is locatedhe CF gene is a recessive gene.Thismeans a person can carry one copy of the gene andstill not be affected by the disease.However if this person has children with anothererson who carries the Cf genethere is a 25 chance that their children will inherit twoopies of the gene and sufferfrom the disease.The test identifies whether pat for cysticrents carrythe defective CF gene.Researchers are also using Fox discovery to find a curefibrosis.They areworking to produce a drug that will change the activity of the Cf geneId alsoattempting to replace the defective gene with one that functions properly.Itdifficultto produce a drug that changes the Cf gene but does not affect the 100000thergenes of human.But Fox discovery has at least given a chance for the cure othe CF
1.A person with ( ) of a harmful recessive gene will be affected
A.one copy
B two opies
C.no copies
D three copies.
2.We can find answers to the following questions in the passage except ()
A.Do people with CF live longer than they did in the past.
B Describeused to treat CF
C.Evaluate the current methods used to treat CF
D.Describe the drugs used to treat CF
3.The following statements are true except ()
A Only one quarter of people will have chance to have the disease.
B.Fox discovery help scientist develop tests that identify carriers of the CF gene
C.Scientist has already produced a drug to CF
D.To produce a drug is not easy because it should changes the CF gene but notaffectothers
4.The word “recessive” (line 6) probably means ()
A.hidden
B concealing
C.faint
D covered
5.The best title for the passage would be ()
A.Why People Have CF
B.The Drugs Used to Treat CF
C.The Methods of Curing CF
D.TheSignificance of the DiscoveryCystic Fibrosis Gene
第2题：
Over eight months the scientists tested 20 drugs, all with negative results. Finally 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. ”
第3题：
The human can react to any situation, some of which he may never have imagined.()
第4题：
Brain researchers have discovered that the formation of new habits can be
A．predicted.
B．regulated.
C．traced.
D．guided.
第5题：
Ethosuzimide, which was developed in the 1950s, is commonly used to treat epilepsy, 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. ”
第6题：
It isn't said in the passage that L-GG can be used to ______.
A) lessen symptoms of Crohn's disease
B) fight against rotavirus
C) treat traveler' s diarrhea
D) treat intestinal upsets caused by antibiotics
第7题：
The discovery that the drugs extend the life span of roundworms could have important 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. ”
第8题：
If cloned animals could be used as organ donors, ().
A、people don’t have to worry about cloning twins for transplants
B、raising animals such as pigs can help solve the problem
C、the human body attacks and destroys tissue from other species
D、it may be more efficient to produce such animals by cloning than by cur
第9题：
There may also be other targets not yet explored that affect aging and neuromuscular 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. ”
选项C：该选项指出：“蛔虫实际上并不是理想的实验对象，因为蛔虫不是人类，尽管两者分子结构相同。”显然，这个选项与原文主旨完全背离。连实验对象都是错误的话，文章的结论就更加不可能是正确的。这个选项应该排除。
选项G：该选项指出：“这种药物已经用于延缓人类衰老了，虽然还需要更多的证据来证明这种药物真的会起作用”。这种论点显然是不对的;没有做过实验怎么能够就冒然使用呢?而且与文中提到的“目前还没有在人类身上做实验”这一点完全相左。这个选项也是明显的干扰选项。第10题：
Why do the American doctors think of using laser light to treat heart disease?
A．Beeause laser light is quite powerful．
B．Because laser light is penetrating．
C．Because laser light can destroy the blocking materials in human’s artery．
D．Because laser light can travel through the human body．