MOOCs (Massive Open Online Courses) are free, but without tutoring, and are open to anyone, anywhere in the world. The courses are flexible -- normally three to five hours of study a week -- done at any time, short (5 to 10 weeks) and video-rich. They are also heavily dependent on crowd sourcing: you can discuss a course with fellow students through online forums, discussion boards and peer review. Students don't have to finish the courses, pass assessments or do assignments, but, if they do, they get a certification of participation. The Open University launched FutureLearn, the UK's answer to US platforms such as Coursera, EdX and Udacity, which have been offering MOOCs from top US universities for the past two years. The response has been incredible, with more than three million people registering worldwide. Meanwhile, in 2012, Edinburgh University became the first non-US institution to join Coursera's partnership, comprising 13 universities. "We already run 50 online master's degrees, so this was a logical expansion," says Professor Jeff Haywood, Edinburgh's vice-principal. "It's an investment in teaching methods research. How am I going to teach introductory philosophy to 100,000 people? That's what I call educational R&D." He adds "If you look ahead 10 years, you'd expect all students graduating to have taken some online courses, so you've got to research that. Our MOOCs are no more in competition with our degrees than a lifelong learning course because they don't carry credits." Cooperation is key, Haywood stresses. It is far better to offer 20-30 courses in your own areas of expertise and let other institutions do likewise. Professor Mike Sharples, FutureLearn's academic lead, goes further: "We've tied the elements available before into a package of courses offered by leading universities worldwide on a new software platform, with a new way of promoting it and also a new social-learning teaching method. You won't just receive an exam, but be able to discuss and mark each other's assignments." Bath... MOOCs have these features EXCEPT that _ . A) MOOCs have a platform for learners to share their learning experience B) MOOCs provide teachers' instructions if you have some difficulty C) MOOCs can be adjusted according to people's learning pace D) MOOCs are free of charge for anyone
B

Teens who become addicted to their cellphones may be placing their health at risk by harming their ability to sleep well,a new Swedish study suggests. "The message is that teenagers who use their cellphones excessively are much more stressed, much more restless, much more tired, and have a great tendency to develop sleep deprivation as a result of their calling habits, " said the study author Dr. Gaby Bader. He focused on the experiences of 21 healthy Swedish boys and girls between the ages of 14 and 20. The teens kept what the authors described as "regular working/studying hours" and were not previously diagnosed with any particular sleep irregularity. He observed that the above-15 call group kept more irregular sleeping hours than the lower-use group,had more difficulty falling asleep,more difficulty waking up,and experienced more sleep disruptions . Bader said that among young people,a ly recent technological invention like the cellphone has quickly become existed nearly everywhere,giving rise to considerable pressure to keep in touch. And this pressure can develop into an addiction,with serious negative results for teenager health. "We see more and more people--especially the young generation-- who grew up with these kinds of items and gadgets in their hands," Bader said. "And they become dependent on the technology. So,we have to teach young people to be structured. To know when to have the cellphone on,and when to switch it off. To avoid becoming the slave of technology,instead of the master. " Dr. Mary Carskadon expressed little surprise with the finding. " Interpersonal contact is one of the things that's best at keeping us awake," she observed. "And so,a young person receiving cellphone texts or phone calls is going to have more deep disturbances. And they are going to be tired and restless,and probably,as a result,going to use more stimulants .And judgment is not always the best in our teenage years. So, that's where I think parental attention to this issue may be useful. " Teens who become addicted to their cellphones will become . A) too anxious to relax. B) unable to stay still. C) unable to have real rest. D) excited to forget sleep.
A

With its 190 million inhabitants, Brazil has the largest population in Latin America and ranks fifth in the world. However, Brazil's population growth rate has dropped greatly and Brazilian women now have only 2.7 children on average. This achievement really becomes the envy of many other Third World countries. Brazil has become one of the developing world's great successes at reducing population growth-----but more by accident than design. While countries such as India have made joint efforts to reduce birth rates, Brazil has had a better result without really trying, says George Martine at Harvard. Martine _ , among other things, soap operas(TV series) and installment plans introduced in the 1970s. Both played an important, although indirect role in lowering the birth rate. Brazil is one of the world's biggest producers of soap operas. Globo, Brazil's most popular television network, shows three hours of soaps six nights a week, while three others show at least one hour a night. Most TV series are based on wealthy characters living the high life in big cities. "Although they have never really tried to work in a message towards the problems of reproduction , they describe middle and upper class values-----not many children, different attitudes towards sex, women working," says Martine. "They sent this image to all parts of Brazil and made people conscious of other patterns of behavior and other values, which were put into a very attractive package." Meanwhile, the installment plans tried to encourage the poor to become consumers. "This led to an enormous change in consumption patterns and showed that consumption was in contradiction with unlimited reproduction," says Martine. The phrase "puts it down to"(Line1, Para. 3) is closest in meaning to " _ ". A) attributes it to B) finds it a reason for C) sums it up as D) compares it to
A