6．Over the last 15years，digital communication has brought in more changes than the printing press did in 1570．And those most likely to use them in this world are teenagers，whose brains appear to have an extraordinary volume to adapt to the world around them，according to Dr Jay Giedd，a（n） （51）Bbrain expert．
We are now discovering that，as a species，our brains during the teenage years are still flexible and capable of （52）C．Having a more flexible brain，（53）A，means that certain parts of it，such as desire control and the ability to make long-term decisions，haven't developed yet，which may also explain why we spend a（n） （54）D period living under the protection of our parents rather than leaving home at the age of 12or 13．This also means that the teenage brain can adapt to new technology，enabling teenagers to（55）A the increasing pace of digital technology and giving them an advantage when it comes to multitasking．
In the USA，on average teenagers spend 8.5hours a day using computers，mobiles，and other devices to learn，interact，and play．This increases to 11.5hours if you include all of the（56）B that goes on，such as talking on the phone while watching TV．As they stare at these screens，they're taking in and sorting through an incredible amount of information．
There are （57）C about how social media is affecting the way the brain learns to （58）D，as one of the most important skills that we learn as children is how to make friends and interact with people around us．Geidd says that a lot of what goes on inside our brains is social．Social interactions are now being （59）A by technology-you could have hundreds of friends，all of whom are real people that you interact with and scientists aren't sure whether we'll be able to develop the same（60）D using social media．
There is a（n） （61）A of the growing digital trend：YouTube shows the teenagers all over the world are watching the same videos and laughing at the same jokes，indicating that they are more （62）B than teenagers in the past．They may be keen on （63）B their friends and posting updates on social media sites，but teenagers today are probably going to have access to technology and （64）Bsocial and educational opportunities that anyone with a less flexible brain may have trouble imagining．Nevertheless，there is a cut-off point，and by the age of 30，our brains in their ways，making it more（65）C for us to adapt and cope with new technologies．
| 51．A．digital | B．adolescent | C．surgical | D．artificial |
| 52．A．functioning | B．noticing | C．adjusting | D．deciding |
| 53．A．however | B．therefore | C．otherwise | D．instead |
| 54．A．natural | B．glorious | C．limited | D．extended |
| 55．A．keep up with | B．come up with | C．put up with | D．end up with |
| 56．A．gossiping | B．multitasking | C．interacting | D．playing |
| 57．A．reports | B．curiosities | C．concerns | D．talks |
| 58．A．memorize | B．sort | C．imagine | D．socialize |
| 59．A．changed | B．controlled | C．troubled | D．interrupted |
| 60．A．trends | B．attitudes | C．societies | D．skills |
| 61．A．advantage | B．distraction | C．indication | D．history |
| 62．A．absent-minded | B．global-minded | C．quick-minded | D．serious-minded |
| 63．A．accessing | B．texting | C．discovering | D．watching |
| 64．A．on the whole | B．as a result | C．in other words | D．by all means |
| 65．A．flexible | B．important | C．difficult | D．incredible |
