More than 60,000 people have purchased the PTKs since they first became available without prescriptions last years, according to Doug Fogg, chief operating officer of Identigene, which makes the overthecounter kits. More than two dozen companies sell DNA tests directly to the public, ranging in price from a few hundred dollars to more than $2500.
Among the most popular : paternity and kinship testing , which adopted children can use to find their biological relatives and families can use to track down kids put up for adoption. DNA testing is also the latest rage among passionate genealogists—and supports businesses that offer to search for a family’s geographic roots。
Most tests require collecting cells by swabbing saliva in the mouth and sending it to the company for testing. All tests require a potential candidate with whom to compare DNA。
But some observers are skeptical, “There is a kind of false precision being hawked by people claiming they are doing ancestry testing,” says Trey Duster, a New York University sociologist. He notes that each individual has many ancestors—numbering in the hundreds just a few centuries back. Yet most ancestry testing only considers a single lineage, either the Y chromosome inherited through men in a father’s line or mitochondrial DNA, which is passed down only from mothers. This DNA can reveal genetic information about only one or two ancestors, even though, for example, just three generations back people also have six other greatgrandparents or, four generations back, 14 other greatgreatgrandparents。
Critics also argue that commercial genetic testing is only as good as the reference collections to which a sample is compared. Databases used by some companies don’t rely on data collected systematically but rather lump together information from different research projects. This means that a DNA database may have a lot of data from some regions and not others, so a person’s test results may differ depending on the company that processes the results. In addition, the computer programs a company uses to estimate relationships may be patented and not subject to peer review or outside evaluation。
26.In paragraphs 1 and 2 , the text shows PTK’s
［A］easy availability.［B］flexibility in pricing。
［C］successful promotion.［D］popularity with households。
27.PTK is used to
［A］locate one’s birth place.［B］promote genetic research。
［C］identify parentchild kinship. ［D］choose children for adoption。
28.Skeptical observers believe that ancestry testing fails to
［A］trace distant ancestors.［B］rebuild reliable bloodlines。
［C］fully use genetic information.［D］achieve the claimed accuracy。
29.In the last paragraph ,a problem commercial genetic testing faces is
［A］disorganized data collection.［B］overlapping database building。
［C］excessive sample comparison.［D］lack of patent evaluation。
30.An appropriate title for the text is most likely to be
［A］ Fors and Againsts of DNA Testing［B］DNA Testing and It’s Problems
［C］DNA Testing Outside the Lab［D］Lies behind DNA Testing
Text 3
The relationship between formal education and economic growth in poor countries is widely misunderstood by economists and politicians alike. Progress in both areas is undoubtedly necessary for the social, political and intellectual development of these and all other societies; however, the conventional view that education should be one of the very highest priorities for promoting rapid economic development in poor countries is wrong. We are fortunate that is it, because building new educational systems there and putting enough people through them to improve economic performance would require two or three generations. The findings of a research institution have consistently shown that workers in all countries can be trained on the job to achieve radically higher productivity and, as a result, radically higher standards of living。
Ironically, the first evidence for this idea appeared in the United States. Not long ago, with the country entering a recessing and Japan at its prebubble peak, the U.S. workforce was derided as poorly educated and one of the primary cause of the poor U.S. economic performance. Japan was, and remains, the global leader in automotiveassembly productivity. Yet the research revealed that the U.S. factories of Honda, Nissan, and Toyota achieved about 95 percent of the productivity of their Japanese counterparts—a result of the training that U.S. workers received on the job。
More recently, while examining housing construction, the researchers discovered that illiterate, non-English-speaking Mexican workers in Houston, Texas, consistently met best-practice labor productivity standards despite the complexity of the building industry’s work。
What is the real relationship between education and economic development? We have begun to suspect that continuing economic growth promotes the development of education even when governments don’t force it. After all, that’s how education got started. When our ancestors were hunters and gatherers 10,000 years ago, they didn’t have time to wonder much about anything besides finding food. Only when humanity began to get its food in a more productive way was there time for other things。
As education improved, humanity’s productivity potential increased as well. When the competitive environment pushed our ancestors to achieve that potential, they could in turn afford more education. This increasingly high level of education is probably a necessary, but not a sufficient, condition for the complex political systems required by advanced economic performance. Thus poor countries might not be able to escape their poverty traps without political changes that may be possible only with broader formal education. A lack of formal education, however, doesn’t constrain the ability of the developing world’s workforce to substantially improve productivity for the foreseeable future. On the contrary, constraints on improving productivity explain why education isn’t developing more quickly there than it is。
31.The author holds in paragraph 1 that the importance of education in poor countries
［A］is subject to groundless doubts. ［B］has fallen victim of bias。
［C］is conventionally downgraded. ［D］has been overestimated。
32.It is stated in paragraph 1 that construction of a new educational system
［A］challenges economists and politicians. ［B］takes efforts of generations。
［C］demands priority from the government.［D］requires sufficient labor force。
33.A major difference between the Japanese and U.S workforces is that
［A］the Japanese workforce is better discipli
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