第二篇
“Don’t Drink Alone” Gets New Meaning
In what may be bad news for bars ans pubs, an European research group has found that people drinking alcohol outside of meals have a significantly higher risk of cancer in the mouth and neck than do those taking their libations with food. Luigino Dal Maso and his colleagues studied the drinking patterns of 1, 500 patients from four cancer studies and another 3, 500 adults who had never had cancer.
After the researchers accounted for the amount of alcohol consumed, they found that individuals who downed a significant share of their alcohol outside of meals faced at least a 50 to 80 percent risk of cancer in the oral cavity, pharynx, and esophagus, when compared with people who drank only at meals. Consuming alcohol without food also increased by at least 20 percent the likelihood of laryngeal cancer. “Roughly 95 percent of cancers at these four sites traced to smoking or drinking by the study volunteers,” Dal Maso says. The discouraging news, his team reports, is that drinking with meals didn’t eliminate cancer risk at any of the sites.
For their new analysis, the European scientists divided people in the study into four groups, based on how many drinks they reported having in an average week. The lowest-intake group included people who averaged up to 20 drinks a week. The highest group reported downing at least 56 servings of alcohol weekly for an average of eight or more per day. Cancer risks for the mouth and neck sites rose steadily with consumption even for people who reported drinking only with meals. For instance, compared with people in the lowest-consumption group, participants who drank 21 to 34 alcohol servings a week at least doubled their cancer risk for all sites other than the larynx. If people in these consumption groups took some of those drinks outside meals, those in the higher conumption group at least quadrupled their risk for oral cavity and esophageal cancers.
People in the highest-consumption group who drank only with meals had 10 times the risk of oral cancer, 7 times the risk of pharyngeal cancer, and 16 times the risk of esophageal cancer compared with those who averaged 20 or fewer drinks a week with meals. Incontrast, laryngeal cancer risk in the high-intake, with-meals-only group was only triple that in the low-intake consumers who drank with meals.
“Alcohol can inflame tissues. Over time, that inflammation can trigger cancer.” Dal Maso says. He suspects that food reduced cancer risk either bypartially coating digestive-tract tissues of by scrubbing alcohol off those tissues. He speculates that the reason laryngeal risks were dramatically lower for all study participants traces to the tissue’s lower exposure to alcohol.
36. Researchers have found that the risk of cancer in the mouth and neck is higher with people_____
A. who drink alcohol outside of meals
B. who drink alcohol at meals
C. who never drink alcohol
D. who drink alcohol at bars and pubs
37. Which of the following is NOT the conclusion made by the researchers about “drinking with meals”?
A. It has a lower risk of cancer than drinking without food
B. It may also be a cause of cancer
C. It increases by 20 percent the possibility of cancer in all sites
D. It does not eliminate cancer risk at any of the sites
38. Approximately how many drinks do the lowest-intake group average per day?
A. 3 drinks B. 8 drinks C. 20 drinks D. 56 drinks
39. Which cancer risk is the lowest among all the four kinds of cancer mentioned in the passage?
A. Oral cancer B. Laryngeal C. Pharyngeal cancer D. Esophageal cancer
40. According to the last paragraph, tissue’s lower exposure to alcohol_____
A. explains why inflammation triggers cancer
B. account for why food can coat digestive-tract tissues
C. is the reason why food can scrub alcohol off tissues
D. reduces the risk of laryngeal cancer
第三篇
Clone Farm
Factory farming could soon enter a new era of mass production. Companies in the US are developing the technology needed to “clone” chickens on a massive scale. Once a chicken with desirable traits has been bred or genetically engineered, tens of thousands of eggs, which will hatch into identical copies, could roll off the production lines every hour. Billions of clones could be produced each year to supply chicken farms with birds that all grow at the same rate, have the same amount of meat and taste the same.
This, at least, is the vision of the US’s National Institute of Science and Technology, which has given Origen Therapeutics of Burlingame, California, and Embrex of North Carolina $4.7 million to help fund research. The prospect has alarmed animal welfare groups, who fear it could increase the suffering of farm birds.
That’s unlikely to put off the poultry industry, however, which wants disease resistant birds that grow faster on less food. “Producers would like the same meat quantity but to use reduced inputs to get there,” says Mike Fitzgerald of Origen. To meet this demand, Origen aims to “create an animal that is effectively a clone”, he says. Normal cloning doesn’t work in birds because eggs can’t be removed and implanted, Instead, the company is trying to bulk-grow embryonic stem cells taken from fertilized eggs as soon as they’re laid. “The trick is to culture the cells without them starting to distinguish, so they remain pluripotent,” says Fitzgerald.
Using a long-established technique, these donor cells will then be injected into the embryo of a freshly laid, fertilized recipient egg, forming a chick that is a “chimera”. Strictly speaking a chimera isn’t a clone, because it contains cells from both donor and recipient. But Fitzgerald says it will be enough if, say, 95 percent of a chicken’s body develops from donor cells. “In the poultry world, it doesn’t matter if it’s not 100 percent,” he says.
Another challenge for Origen is to scale up production. To do this, it has teamed up with Embrex, which produces machines that can inject vaccines into up to 50,000 eggs an hour. Embrex is now trying to modify the machines to locate the embryo and inject the cells into precisely the right spot without killing it.
In future, Origen imagines freezing stem cells from different strains of chicken. If orders come in for a particular strain, millions of eggs could be produced in months or even weeks. At present, maintaining all the varieties the market might call for is too expensive for breeders, and it takes years to bread enough chickens to produce the billions of eggs that farmers need.
41.Which statement is the best description of the new era of factory farming according to the first paragraph?
A. Eggs are all genetically engineered
B. Thousands of eggs are produced every hour
C. Cloned chickens are bulk-produced with the same growth rate, weight and taste.
D. Identical eggs can be hatched on the production lines
42. Which institution has offered $4.7 million to fund the research?
A. The US’s National Institute of Science and Technology.
B. Origen Therapeutics of Burlingame, California
C. Embrex of North Carolina
D. Animal welfare groups
43. In the third paragraph, by saying “Producers would like the same meat quantity but to use reduced inputs to get there.” Mike Fitzgerald means that he wishes_____.
A. chickens’ quality could be maintained but with less investment
B. chickens’ taste could be improved but at less costs
C. chickens’ growth are could be quickened but with less inputs
D. chickens could grow to the same weight but with less feed.
44. Which of the following statements about Origen and Embrex is correct according to the fifth paragraph?
A. Origen and Embrex will jointly invent machines to increase production
B. Origen wants to purchase an efficient donor cells injecting machine
C. Origen has joined hands with Embrex in producing cell-injecting machines.
D. Origen is the leading company in producing embryo-locating machines
45. The technology of freezing stem cells from different strains of chicken can do all the following EXCEPT that_____.
A. farmers can order certain strains of chicken only
B. Origen can supply all the strains of chicken the market might need
C. chicken farmers order certain strains of chicken for economic reason
D. chicken famers can be supplied with whatever strain they need
