单选题Read the following article from a newspaper and answer questions 19-25. For questions 19-25, choose the correct answer A, B, C or D. Are You Afraid of MOOCs? Are MOOCs and other online materials a threat to quality public higher education, and to our role as professors? The members of the philosophy department at San Jose State University think so. They recently issued an open letter to Michael Sandel, a professor of Harvard University, objecting to his role in encouraging the use of MOOCs at public universities. The controversy stems from San Jose State's contract with edX, a company that provides MOOCs, including one based on Sandel's course on justice at Harvard. San Jose State has agreed to use materials provided by edX, but the philosophy department has refused to use Sandel's online lectures in its courses. Though MOOCs are still new, many of the arguments presented by the San Jose State philosophy professors do not ring true in light of my experience. We should begin by distinguishing two issues. The philosophy professors state that they have felt pressured by their administration to use the materials from Sandel's course. The administration denies exerting any such pressure. Whatever the truth of the matter, that is an issue of academic freedom, and not about the pedagogical merits of using MOOCs and other online materials. I certainly agree that professors should be, responsible for the content and pedagogy in their own courses. The real issue, then, is whether the availability and use of online materials, whether through MOOCs or through other channels, is a threat to quality education, especially at public universities. Many of the arguments presented in the letter presuppose an either/or, all-or-nothing approach when it comes to face-to-face versus online teaching. But the whole point of a hybrid, or blended, course is that it combines both. And it is difficult to see why it makes a great deal of difference whether the online content is delivered via a MOOC or not. Nothing will ever replace the face-to-face discussions that occur in the classroom. But in many traditional, on-campus courses, little discussion occurs. In a lecture course with hundreds, or even just scores, of students, much of the time in the classroom is inevitably spent with the professor lecturing and the students(hopefully)taking notes-or at least listening attentively. In courses with a significant lecture component, the advantages of using online lectures are undeniable. I know from my own experience that, if my attention wanes for a few moments, it is very convenient to simply go back and play a portion again. One can do the same if one doesn't quite understand something the first time. And one need not miss material to take a bathroom break. The availability of high-quality online lectures is an opportunity to rethink how we spend our time in the classroom. If an online lecture presents the material, or walks students through an argument, we are freed to spend more time discussing the aspects of the material that are most difficult-or most interesting. We can do other kinds of activities that we might not have time for if we felt obliged to present the material in the traditional way. Yes, hybrid courses usually involve less face-to-face time, but that time can be better and more effectively spent. The crucial thing is that the instructor remains in the driver's seat -and that takes us back to academic freedom. As long as individual professors are choosing what material to assign or recommend, running their in-class discussions and adding material that they think is not adequately covered in the online lectures, choosing the assignments and tests, and grading those tests, there is no threat to the professoriate, or to the quality of education at universities, public or otherwise.

单选题To Tweet or Not to Tweet The economy may be troubled, but one area is thriving: social media. They begin with Facebook and extend through a dizzying array of companies that barely existed five years ago: Twitter, LinkedIn, Groupon, Yammer, Yelp, Flickr, Ning, Digg—and the list goes on. These companies are mostly private but have attracted the ardent attention of Wall Street and investors, with Facebook now worth a purported ＄75 billion and Groupon valued at close to ＄25 billion. There can be little doubt than these companies enrich their founders as well as some investors. But do they add anything to overall economic activity? While jobs in social media are growing fast, there were only about 21,000 listings last spring, a tiny fraction of the 150 million-member U.S. workforce. So do social-media tools enhance productivity or help us bridge the wealth divide? Or are they simply social-entertaining and diverting us but a wash when it comes to national economic health? The answers are vital, because billions of dollars in investment capital are being spent on these ventures, and if we are to have a productive future economy, that capital needs to grow the economic pie—and not just among the elite of Silicon Valley and Wall Street. The U.S. retains a competitive advantage because of its ability to innovate, but if that innovation creates services that don't turn into jobs, growth and prosperity, then it does us only marginal good. The problem is that these tools are so new that it is extremely difficult to answer the questions definitively. Flash back nearly 20 years and the same questions were being asked about the first Internet wave. Were Netscape and the Web enhancing our economy, or were people just spending more time at work checking out ESPN.com? Official statistics weren't designed to capture the benefits, and didn't—until statistics mavens at the Federal Reserve, urged on by Alan Greenspan, refined the way they measured productivity. As a result of these somewhat controversial innovations, the late 1990s became a period of substantial technology-driven gains. It is possible that the same gap exists today, that social-media tools are indeed laying the groundwork for new industries and jobs but aren't yet registering on the statistical radar. Many companies believe social media make them more competitive. Ford and Zappos, for instance, use Twitter to market their products and address consumer complaints. Countless corporations have created internal Facebook pages and Yammer accounts for employees to communicate across divisions and regions. Industry groups for engineers, doctors and human-resources professionals have done the same to share new ideas and solutions on a constant basis rather than episodically at conferences. Staffing companies have been especially keen on social media; a senior executive at Manpower told me we should think of social-media tools as today's version of the telephone. One big question is what proportion of that benefit will be captured economically by consumers vs. corporations. Sure, social media allow people to compare prices and quality and assess which companies are good to work for and where jobs might be. They also may enhance education and idea sharing, but the caveat is that the people who use these tools are the ones with higher education and income to spend on technology, not the tens of millions whose position in today's world has eroded so sharply. According to a recent Pew Foundation study, only 45% of adults making less than ＄30,000 have access to broadband, which is an essential component of using content-rich social media effectively. And that is the rub. Like so many things these days, social media contribute to economic bifurcation. Dynamic companies are benefiting from these tools, even if the gains are tough to nail down in specific figures. Many individuals are benefiting too, using Linkedln to find jobs and Groupon to find deals. Bui for now, the irony is that social media widen the social divide, making it even harder for the have-nots to navigate. They allow those with jobs to do them more effectively and companies that are profiting to profit more. But so far, they have done little to aid those who are being left behind. They are, in short, business as usual.

单选题As soon as he was confronted with the evidence, he admitted that he had stolen the car.

单选题We can arrive there on time but we"d better admit of some happenings on the trip.

单选题He lost his money gambling at cards.

单选题The city"s population is in decline.

单选题assist

单选题Even sensible men do absurd things sometimes.

单选题I thought of a brilliant solution to the problem.

单选题Anyhow , I must be going now.

单选题assume

单选题break off

单选题abandon

单选题candy

单选题This is the ______ piano on which the composer created some of his greatest works.

单选题I never regretted paying $100 for the bookcase. As a matter of fact I would gladly have paid ______ for it.

单选题The car crashed into a lamp pole and was seriously damaged.

单选题It is a pity that he is blind ______ his own fault.

单选题audio

单选题The man lost in the desert was desperate for water.