根据下列材料，请回答下列各题 The relentless march of technology into everyday life has a

lways given rise to debate about whether it is a good or a bad thing．Some believe that the Internet and computer software are making humans more stupid or shallow．But others argue that computer programs in the form. of video games can make people smarter or improve specific skills，suchas spatial awareness． Shawn Green and Alexandre Pouget，from the University of Rochester，in New York state，set out to find an answer．Their study，reported in Current Biology，involved a number of experiments．In one，the participants had to watch 12 dots moving randomly on a screen and quickly assess their aggregate direction of movement．Another test asked participants to work out the direction of specific sounds embedded within stereo white noise．In both tests the video．gamers did better．However，the scientists were aware that gamers could have been born with improved abilities to perform. such tasks，which were possibly what attracted them to gaming in the first place．Consequently，a third test was necessary to see if these abilities could have been learnt． The non．gaming volunteers were put through 50 hours of video—game training．For some this involved playing fast-action shoot-em-up games such as“Call of Duty 2”and“Unreal Tournament”．but others were given a slow-moving life—strategy game，“The Sims 2”．The researchers found that those trained with action games raised their performance to the level of the experienced garners．Moreover，they were more efficient in their use of visual or auditory evidence than those playing with the Sims． The researchers conclude that fast action video-games players develop an enhanced sensitivity to what is going on around them and that this may help with activities such as multitasking，driving，reading small print，navigation and keeping track of friends or children in a crowd．The precise neural mechanism for this effect，however，is still unknown． What is known is that people make decisions based on probabilities that are constantly being calculated and refined in their heads--something called“probabilistic inference”．The brain collects small pieces of information，eventually gathering enough to make an accurate decision．When driving a car，for example，many probabilities will be collated to make decisions such as whether or not to brake．The more efficient someone is at coUecting visual and auditory information，the faster he can reach the threshold needed to make a decision． Shawn Green，Alexandre Pouget suggest that reaction times in the population will probably improve with the rise of fast—action videO—games．There are a lot of players：last year a report estimated that 67％of American households contained at least one video-gamer．And if video—gamers are really better equipped to make quick decisions．they might also turn out to be better drivers and end up in fewer accidents．However，the notion that gamers acquire some minor physical skills may not pacify concerned parents．What，after all，of the skills they are not acquiring when shooting virtual cops instead of reading or talking？ The problem of first two experiments lies in that______．

A.they are too simple to support researchers’assumption

B.they do lead to unambiguous conclusion

C.they focus on irrelevant skills of participants

D.they do not seperate video-gamers from non-gamers