One baby born with a defective windpipe now has hope of breathing normally thanks to 3-D printing technology, NPR reported. Garrett Peterson, now 18 months old, was born with tracheomalacia , leaving him unable to breathe. The condition terrified his parents, who turned to specialist Dr. Glenn Green at the University of Michigan for a possible treatment. Along with Scott Hollister, a biomedical engineer who runs the university's 3-D printing lab, Green designed a device that can hold open Garrett's windpipe until it's strong enough to function independently. After taking a CT scan of Garrett's windpipe to make a replica of it, they made the "splint" with a 3-D printer. "It's like a protective shell that goes on the outside of the windpipe, and it allows the windpipe to be tacked to the inside of that shell to open it up directly," Green told NPR. On January 31, Garrett had his surgery. Surgeon Dr. Richard Ohye opened up Garrett's chest and saw that his windpipe had completely collapsed and one of his lungs was completely white -- a condition Ohye had only seen in dead bodies. After eight hours of surgery and careful placement of a splint on either side of Garrett's windpipe, it was time for the big test: What would happen when they let air flow through the windpipe into Garrett's lungs? Though he still remains in the hospital, Garrett has gotten stronger and needs less assistance breathing in the weeks since his surgery. His parents are overjoyed, saying he's starting to act more interactive and alert. As Garrett grows, the splint will expand and eventually dissolve in his body as his own windpipe strengthens enough to work independently. 3-D printing technology has allowed doctors to help patients in ways that they hope will continue to grow. "We're talking about taking something like dust and converting it into body parts," Green said. "And we're able to do things that were never possible before." We can learn from the passage that _ . A) Garrett is out of hospital with the help of 3-D printing technology. B) The splint will exist in Garrett's body for ever. C) It is difficult to operate the 3-D printer. D) Garrett's condition is critical.
D
"I drink caffeine to stay awake. It has positive effects on me. I'm healthy, and there's nothing wrong with me," said Sarah Green, a freshman, who consumes many caffeine drinks to stay awake in completing the many tasks in her busy schedule. Caffeine is known to have many positive and negative consequences, and now that there might be an additional positive effect may have been discovered. A study suggests that a skin lotion containing caffeine, which is also found in green tea, may reduce the risk of skin cancer. Two lotion tests were conducted on hairless mice that were exposed to high levels of ultraviolet radiation . As a result, the lotion reduced the number of tumors each mouse developed. Unlike sunscreen , the new lotion is applied after exposure to the ultraviolet rays. Rays from the sun can cause genetic changes in the skin that can lead to skin cancer. Caffeine obstructs this action and causes the diseased cells to kill themselves. "I know that caffeine has been found in certain drinks and it causes increased activity of the nervous system, and increased blood pressure on blood vessels . I don't know of any positive effects of caffeine," health teacher Montego Estes said. Caffeine, found commonly in tea, coffee and soft drinks, provides people with an increase in energy. Half of all American adults consume more than 300 milligrams of caffeine per day. Caffeine is addictive because it uses the same mechanisms as amphetamines , and cocaine and heroin to excite the brain. "This new cream doesn't sound to me as though it would work," junior David Bobbit said, "Caffeine seems to have more negative effects than positive ones." Skin cancer is the most common of all cancers in the US. About one million cases will be diagnosed in the country this year. There will be more than 88,000 new cases of melanoma , the disease's deadliest form of skin cancer. It can be inferred from this passage that _ . A) Sarah Green knows caffeine can protect her from skin cancer B) Exposure to ultraviolet rays is always blamed for skin cancer C) Caffeine will be used in medicine to treat skin cancer patients soon D) In a way, the study on caffeine is good news for many Americans
D
(Question)
Workers who commute by car, bus or train to the office are more likely to suffer from stress and exhaustion, according to a study. Scientists studied 12,000 employees aged between 18 and 65.They found that those who traveled to work by car or public transport reported higher levels of stress and tiredness compared to active commuters who traveled by foot or bicycle. The negative health of public transport users increased with journey time. It is now expected that the study, from Lund University in Sweden, will encourage further investigation into the health effects of commuting and the best forms of transportation. Researcher Erik Hansson said:"Generally car and public transport users suffered more everyday stress, poorer sleep quality, exhaustion and felt that they struggled with their health compared to the active commuters." According to the Office for National Statistics, the average Briton commutes 54 minutes every day. But now the scientists claim that the advantages of daily travel, such as higher pay or housing conditions, need to be weighed against the negative health effects. Income, family background and environmental factors are other things that need to be considered. It may also have a cost effect on industry. According to a Absence and Workplace Health Survey, the U.K. economy lost 190 million working days to absence last year, with each employee taking an average of 6.5 days off sick, costing employers US$27 billion. Hansson added that findings would help to reconsider the balance between economic needs, health, and the costs of working days lost. However, researchers stress that the findings, published in the journal BMC Public Health, do not prove that commuting causes ill health and further research is needed. It hasn't been proved in the study that _ . A) .the balance between economic needs and health is broken B) .more stay at public transport is more harmful to people C) going to work by bus is more tiring than by bike D) commuting causes ill health
(Answer)
D