Part Ⅱ Cloze Video game players may get an unexpected benefit from blowing away bad guys—better vision. Playing "action" video games improves a visual ability 1 tasks like reading and driving at night, a new study says. The ability, called contrast sensitivity function, allows people to discern even subtle changes 2 gray against a uniformly colored backdrop. It's also one of the first visual aptitudes to fade with age. That's 3 a regular regimen of action video game training can provide long-lasting visual power, according to work led by Daphne Bavelier of the University of Rochester. Previous research shows that gaming improves other visual skills, such as the ability to track several objects at the same time and 4 attention to a series of fast-moving events, Bavelier said. "A lot of different aspects of the visual system are being enhanced, 5 one," she said. The new work suggests that playing video games could someday become part of vision-correction treatments, which currently rely mainly on surgery or corrective lenses. " 6 you've had eye surgery or get corrective lenses, exposing yourself to these games should help the optical system to recover faster and better, you need to retrain the brain to make use of the better, crisper information that's coming in 7 a result of your improved eyesight," Bavelier said. Expert action garners in the study played first-person shooters Unreal Tournament 2004 and Call of Duty 2. A group of experienced nonaction garners played The Sims 2, a "life simulation" video game. The players of nonaction video games didn't see the same vision 8 , the study says. Bavelier and others are now trying to figure out exactly why action games 9 seem to sharpen visual skill. It may be that locating enemies and aiming accurately is a strenuous, strength-building workout for the eyes, she said. Another possible 10 is that the unpredictable, fast-changing environment of the typical action game requires players to constantly monitor entire landscapes and analyze optical data quickly. Finally, Bavelier said, the games' rich payoff may also play a role. "It's pleasing to be successful in your mission," she said. "When you combine rewards with these other "factors", then you get much more learning."
It was the kind of research that gave insight into how flu strains could mutate so quickly. The same branch of research concluded in 2005 that the 1918 flu started in birds before passing to humans. Parsing this animal-human 11 could provide clues to 12 the next potential superflu, which already has a name: H5N1, also known as avian flu or bird flu. This potential killer also has a number: 59%. According to the WHO, nearly three-fifths of the people who 13 H5N1 since 2003 died from the virus, which was first reported 14 humans in Hong Kong in 1997 before a more serious 15 occurred in Southeast Asia between 2003 and 2004. (It has since spread to Africa and Europe.) Some researchers argue that those mortality numbers are exaggerated because WHO only 16 cases in which victims are sick enough to go to the hospitals for treatment. 17 , compare that to the worldwide mortality rate of the 1918 pandemic; it may have killed roughly 50 million people, but that was only 10% of the number of people infected, according to a 2006 estimate. H5N1's saving grace—and the only reason we're not running around masked up in public right now—is that the strain doesn't jump from birds to humans, or from humans to humans, easily. There have been just over 600 cases (and 359 deaths) since 2003. But 18 its lethality, and the chance it could turn into something far more transmissible, one might expect H5N1 research to be exploding, with labs 19 the virus's molecular components to understand how it spreads between animals and 20 to humans, and hoping to discover a vaccine that could head off a pandemic.
[解析] 本题考查的是动词用法。provide A to B意为“为B提供A”,A和B均为名词性成分。本句选项给的是动词stop,需要使用它的动名词形式stopping。stopping the next potential superflu为主动意义,不需要用被动态,且本句时态为现在时,需要保持时态一致。综上所述,故选B。