单选题：Questions are based on the following passage. President Obam

Questions are based on the following passage.
President Obama has been taking some heat in technology circles over comments he made at acommencement address over the weekend about iPods and iPads and other digital distractions．Becauseof these things, he said, "information becomes a distraction, a diversion, a form of entertainment,rather than a tool of empowerment, rather than the means of emancipation．"I hate to say this, but he's right．Remember when computers were supposed to save us time? Nowit seems just the opposite．The Intemet just keeps giving us more ways to do nothing.
We have more information than ever before．We're never away from it．The air around us fairlyhums with it．Computers are all around us too--they're on our desks, in our pockets, on our coffeetables．And yet I can't shake the sense that we are all becoming stupider and stupider--and that we are,on average, less well informed today than we were a generation ago.
We're reading e-mail．We're tweeting and retweeting．We're downloading apps, and uploadingphotos．We're updating our Facebook status and reading our news feeds and telling the whole worldwhat we like and don't like, because for some reason we imagine that the whole world actually cares．You know what we're not doing? We're not thinking．We're processing．There's a difference．We're putting our brains into neutral, and revolving (加快转速) the engine．① We're digitally at aloss, clicking on links and swimming through a torrent of useless garbage being thrown at us by idiotsand self-promoters, so-cailed experts and marketing people.
We're immersing ourselves in games like Farmville and Mafia Wars, obsessed about earning energypacks, spending billions of dollars on virtual gardening tools.
We're turning the world around us into a video game, using sites like Foursquare to tell our friendswhere we're eating lunch, and competing to see who can become "mayor" of some restaurant.
Meanwhile, in the midst of all this, Glenn Beck has become an influential television commentator,and Sarah Palin is a credible candidate for president in 2012．You think this is a coincidence?
No way．What's happening is this: we are being so overwhelmed by the noise and junk zooming(嗡嗡声) past us that we're becoming immune to it．We've become a nation of Intemet-powered fools,with an ever-lower threshold for boredom.Beck and Palin are the inevitable outcome of thatdevolution．They are, in fact, what we've created．We have amazing new systems and tools for communicating information．The problem is we'vebecome so fascinated with the means of transmission that we've lost sight of what's actually passingalong over the wires and airwaves.
Sadly, I don't see that changing any time soon．If anything, I imagine it will get worse.
Why does President Obama give a negative comment on digital high-techs? A．Because these high-techs have severely affected our power in the world.
B．Because they only bring us confusing ideas and funny entertainments.
C．Because they are designed to confine our horizons to a certain scope.
D．Because they haven't brought us the effect on our life they are supposed to.