更多"[不定项选择题]共用题干
That scientists have "的相关试题:
[不定项选择题]共用题干
That scientists have cloned a sheep sends academics and the public into a panic at the prospect that humans might be next. That's an understandable reaction.(46)___________,so it's not unreasonable to be concerned that it might threaten human society and dignity.Yet much of the ethical oppo-- sition seems also to grow out of an unthinking disgust. And that makes it hard for even trained scientists and ethicists to see the matter clearly.While human cloning might not offer great benefits to humarnty,no one has yet made a persuasive case that it would do any real harm,either.
(47)_______That would surely be true if a cloned individual were treated as a lesser being, with fewer rights or lower stature.But why suppose that cloned persons wouldn't share the same rights and dignity as the rest of us?A leading ethicist has suggested that cloning would violate the "right to genetic identity".(48)________It makes perfect sense to say that adult persons have a right not to be cloned without their voluntary,informed consent. But if such consent is given,whose "right"to genetic identity would be violated?
So who will likely take advantage of cloning?Perhaps a grieving couple whose child is dying. (49)________But a cloned child born to such dubious parents stands no greater or lesser chance of being loved,or rejected,or warped than a child normally conceived.Infertile couples are also likely to seek out cloning. That such couples have other options(in vitro fertilization or adoption)is not an argument for denying them the right to clone.Or consider an example raised by Judge Richard Posner:a couple in which the husband has some tragic genetic defect. Currently,if this couple wants a genetically related child,(50)________They can reproduce naturally and risk passing on the disease to the child.They can go to a sperm bank and take a chance on unknown genes.They can try in vitro fertilization and dispose of any afflicted embryo though that might be objectionable,too.Or they can get a male relative of the father to donate sperm,if such a relative exists.This is one case where even people unnerved by cloning might see it as not the worst option.
Even if human cloning offers no obvious benefits to humanity,why ban it?In a democratic society we don't usually pass laws outlawing something before there is actual or probable evidence of harm.Most important,human cloning should be governed by the same laws that now protect human rights.A world not safe for cloned humans would be a world not safe for the rest of us.
_______（49）
A.they have four not altogether pleasant options.
B.This might seem psychologically twisted.
C.Theologians contend that to clone a human would violate human dignity.
D.Parents might clone a child to have"spare parts"in case the original child needs an organ transplant.
E.Cloning is a radical challenge to the most fundamental laws of biology.
F.Where did he come up with such a right?
[不定项选择题]共用题干
Changes in Museums
Museums have changed.They are no longer places that one"should"visit;they are places to enjoy and learn.
At a science museum in Ontario,Canada,you can feel your hair stand on end as harmless electricity passes through your body.At the Metropolitan（大城市的）Museum of Art in New York City , you can look at the seventeenth century instruments while listening to their music.At New York's American Museum of Natural History recently,you can help make a bone-by- bone reproduction of the museum's dinosaur（恐 龙）,a beast that lived 200 million years ago.
More and more museum directors are realizing that people learn best when they can somehow become part of what they are seeing.In many science museums,for example,there are no guided tours.The visitor is encouraged to touch,listen,operate,and experiment so as to discover scientific principles for himself. The purpose is not only to provide fun but also to help people feel at home in the world of science.The theory is that people who do not understand science will probably fear it,and those who fear science will not use it to best advantage.
One cause of all these changes is the increase in wealth and leisure time.Another cause is the rising percentage of young people in the population.Many of these young people are college students or college graduates.Leon
F.Twiggs,a young black professor of art once said,"They see things in a new and different way.They are not satisfied to stand and look at works of art;they want art they can participate（参加）in."The same is true of science and history.
Young people who are well-educated like the art they can participate in.
A.Right
B.Wrong
C.Not mentioned
[不定项选择题]共用题干
Beyond the Pap
Scientists have known for some time that virtually all cases of cervical cancer are triggered by a family of viruses called human papillomavirus,or HPV.Most women who become infected with HPV are able to shake off the virus and suffer no apparent long-term consequences to their health.But a few women develop a per- sistent infection that can,for reasons that are not entirely clear,eventually lead to cancerous changes in the cervix。
Now researchers at the Digene Corp.of Beltsville,Maryland,have developed a test that detects an ac- tive HPV infection by looking for its genetic byproducts in the vagina.The HPV test was better than the standard Pap test at finding cervical cancer at any stage,according to two studies published this month in the Journal of the American Medical Association.So far,so good.Unfortunately,the test's false-positive rate- how often it indicated that there was a problem when none existed-was almost twice as high as that for the Pap smear.In these cases,a biopsy of the woman's cervix showed no sign of disease.
And that's the crux of the problem.How many women should undergo what is,when it comes right down to it,unnecessary treatment to find a few more cases of cervical cancer? Shouldn't health officials fodus instead on making sure that more women undergo regular Papsmear examinations?After all,Pap smears,though far from perfect,have helped dramatically lower the death toll from cervical cancer,taking it from the No.1 cause of death due to cancer in American women to the 10th.
Complicating matters is the fact that HPV is a very common infection.In some parts of the US as many as half of all women under age 35 have an active case.Yet 99 out of 100 women who are HPV-positive will never get cervical cancer,estimates Dr.Joanna Cain,vice president of the American College of Obstetricians and Gynecologists."If those 99 women live their lives as if they're going to develop cancer,"she says, "we're not necessarily doing them any good."
At present,the HPV test is approved in the US only to help resolve ambiguous results from a Papsmear test.Many gynecologists believe that HPV will eventually replace the Pap.But they're not willing to aban don it without a lot more detailed information and neither should you.
The author believes that HPV will eventually replace the Pap.
A.Right
B.Wrong
C.Not mentioned
[不定项选择题]共用题干
第二篇
Where Have All the Frogs Gone?
In the 1980s,scientists around the world began to notice something strange:Frogs
were disappearing. More recent research has shown that many kinds of amphibians（两栖
动物）are declining or have become extinct. They have been around for a long time一over
350 million years.Why are they dying out now?
Scientists are seriously concerned about this question.First of all,amphibians are an
important source of scientific and medical knowledge.By studying amphibians,scientists
have learned about new substances that could be very useful for treating human diseases.
Further research could lead to many more discoveries,but that will be impossible if the
amphibians disappear.
The most serious aspect of amphibian loss,however,goes beyond the amphibians
themselves.Scientists are beginning to think about what amphibian decline means for the
planet as a whole.If the earth is becoming unlivable for amphibians,is it also becoming
unlivable for other kinds of animals and human beings as well?
Scientists now believe that amphibian decline is due to several environmental factors.
One of these factors is the destruction of habitat,the natural area where an animal lives.
Amphibians are very sensitive to changes in their habitat.If they cannot find the right
conditions,they will not lay their eggs一These days,as wild areas are covered with
houses,roads,farms,or factories,many kinds of amphibians are no longer laying eggs.
For example,the arroyo toad（蟾蜍）of southern California will only lay its eggs on the
sandy bottom of a slow-moving stream.There are very few streams left in southern
California,and those streams are often muddy because of building projects. Not
surprisingily,the arrovo toad is now in danaer of extinction.
There are a number of other factors in amphibian decline.Pollution is one of them.In
many industrial areas,air pollution has poisoned the rain,which then falls on ponds and
kills the frogs and toads that live there,In farming areas,the heavy use of chemicals on
crops has also killed off arrtphibians.Another factor is that air pollution has led to increased
levels of ultraviolet (UV) light. This endangers amphibians, which seem to be especially
sensitive to UV light. And finally, scientists have discovered a new disease that seems to
be killing many species of arnpttibians in different parts of the world.
All these reasons for the disappearance of amphibians are also good reasons for more
general concern. The destrriction of land, the pollcition of the air and the water, the
changes in our atmosphere, the spread of diseases-these factors affect human beings,
too. Amphibians are especially sensitive to environmental change. Perhaps they are like
the canary （金丝雀）bird that coal miners once used to take down into the mines to detect
poisonous gases. When the canary became ill or died,the miners knew that dangerous
gases were near and their own lives were in danger.
Coal miners once used the canary bird to detect
A.poisonous gases.
B.air pollution.
C.water leakage.
D.radiation.
