单选题 Professor Ashok Goel of Georgia Tech developed an artificially intelligent teaching assistant to help handle the enormous number of student questions in the online class, Knowledge-Based Artificial Intelligence. This online course is a core requirement of Georgia Tech's online Master of Science in Computer Science program. Professor Goel already had eight teaching assistants, but that wasn't enough to deal with the overwhelming number of daily questions from students. Many students drop out of online courses because of the lack of teaching support. When students feel isolated or confused and reach out with questions that go unanswered, their motivation to continue begins to fade. Professor Goel decided to do something to remedy this situation and his solution was to create a virtual assistant named Jill Watson, which is based on the IBM Watson platform. Goel and his team developed several versions of Jill Watson before releasing her to the online forums. At first, the virtual assistant wasn't too great. But Goel and his team sourced the online discussion forum to find all the 40,000 questions that had ever been asked since the class was launched. Then they began to feed Jill with the questions and answers. After some adjustments and sufficient time, Jill was able to answer the students' questions correctly 97% of the time. The virtual assistant became so advanced and realistic that the students didn't know she was a computer. The students, who were studying artificial intelligence, were interacting with the virtual assistant and couldn't tell it apart from a real human being. Goel didn't inform them about Jill's true identity until April 26. The students were actually very positive about the experience. The goal of Professor Goel's virtual assistant next year is to take over answering 40% of all the questions posed by students on the online forum. The name Jill Watson will, of course, change to something else next semester. Professor Goel has a much rosier outlook on the future of artificial intelligence than, say, Elon Musk, Stephen Hawking, Bill Gates or Steve Wozniak.

单选题 There is nothing like the suggestion of a cancer risk to scare a parent, especially one of the over-educated, eco-conscious type. So you can imagine the reaction when a recent USA Today investigation of air quality around the nation's schools singled out those in the smugly green village of Berkeley, Calif, as being among the worst in the country. The city's public high school, as well as a number of daycare centers, preschools, elementary and middle schools, fell in the lowest 10%. Industrial pollution in our town had supposedly turned students into living science experiments breathing in a laboratory's worth of heavy metals like manganese (锰), chromium (铬) and nickel (镍) each day. This in a city that requires school cafeterias to serve organic meals. Great, I thought, organic lunch, toxic campus. Since December, when the report came out, the mayor, neighborhood activists and various parent-teacher associations have engaged in a fierce battle over its validity: over the guilt of the steel-casting factor5, on the western edge of town, over union jobs versus children's health and over what, if anything, ought to be done. With all sides presenting their own experts armed with conflicting scientific studies, whom should parents believe? Is there truly a threat here, we asked one another as we dropped off our kids, and if so, how great is it? And how does it compare with the other, seemingly perpetual health scares we confront, like panic over lead in synthetic athletic fields? Rather than just another weird episode in the town that brought you protesting environmentalists, this latest drama is a trial for how today's parents perceive risk, how we try to keep our kids safe—whether it's possible to keep them safe—in what feels like an increasingly threatening world. It raises the question of what, in our time, 'safe' could even mean. 'There's no way around the uncertainty,' says Kimberly Thompson, president of Kid Risk, a nonprofit group that studies children's health. 'That means your choices can matter, but it also means you aren't going to know if they do.' A 2004 report in the journal Pediatrics explained that nervous parents have more to fear from fire, car accidents and drowning than from toxic chemical exposure. To which I say: Well, obviously. But such concrete hazards are beside the point. It's the dangers parents can't—and may never—quantify that occur all of sudden. That's why I've rid my cupboard of microwave food packed in bags coated with a potential cancer-causing substance, but although I've lived blocks from a major fault line (地质断层) for more than 12 years, I still haven't bolted our bookcases to the living room wall.

单选题 For this part, you are allowed 30 minutes to write a short essay entitled Online Shopping. You should write at least 120 words following the outline given below. 1. 现在网上购物已成为一种时尚 2. 网上购物有很多好处，但也有不少问题 3. 我的建议

单选题 The planet is getting lusher, and we are responsible. Carbon dioxide generated by human activity is stimulating photosynthesis (光合作用) and causing a beneficial greening of the Earth's surface. For the first time, researchers claim to have shown that the increase in plant cover is due to this 'CO2 fertilization effect' rather than other causes. However, it remains unclear whether the effect can counter any negative consequences of global warming, such as the spread of deserts. Recent satellite studies have shown that the planet is harboring more vegetation overall, but pinning down the cause has been difficult. Factors such as higher temperatures, extra rainfall, and an increase in atmospheric CO2—which helps plants use water more efficiently—could all be boosting vegetation. To home in on the effect of CO2, Randall Donohue of Australia's national research institute, the CSIRO in Canberra, monitored vegetation at the edges of deserts in Australia, southern Africa, the US Southwest, North Africa, the Middle East and central Asia. These are regions where there is ample warmth and sunlight, but only just enough rainfall for vegetation to grow, so any change in plant cover must be the result of a change in rainfall patterns or CO2 levels, or both. If CO2 levels were constant, then the amount of vegetation per unit of rainfall ought to be constant, too. However, the team found that this figure rose by 11 per cent in these areas between 1982 and 2010, mirroring the rise in CO2 (Geophysical Research Letters, doi. org/mqx). Donohue says this lends 'strong support' to the idea that CO2 fertilization drove the greening. Climate change studies have predicted that many dry areas will get drier and that some deserts will expand. Donohue's findings make this less certain. However, the greening effect may not apply to the world's driest regions. Beth Newingham of the University of Idaho, Moscow, recently published the result of a 10-year experiment involving a greenhouse set up in the Mojave Desert of Nevada. She found 'no sustained increase in biomass' when extra CO2 was pumped into the greenhouse. 'You cannot assume that all these deserts respond the same,' she says. 'Enough water needs to be present for the plants to respond at all.'

单选题 面子是某个人在他人眼中的社会地位和名声。中国人一生都用言语和行动维护和提升面子。可以小到谁先上电梯，也可以大到数百万美元的合同授予(awarding)。没有面子也就没有影响力。即使是无意中让别人没面子，也是极其严重的冒犯(dishonor)，可能意味着断绝关系。即使是开玩笑，中国人也不会公开批评、忽视或者取笑他人。点评别人的成绩时，也是先说优点，再讲不足。

单选题Women in 2011 made no significant gains in winning more top US business jobs, according to a study, but the head of the study said women are poised to make 27 in the year ahead. The number of women who were board directors, corporate officers or top earners at Fortune 500 companies remained 28 unchanged, said the study by Catalyst, a nonprofit group that 29 Opportunities for women in business. The percentage of companies with women on the board of directors was 15.1 percent this year, compared with 14.8 percent in 2010, Catalyst said. Also, the percentage of corporate officer positions 30 by women was 15.7 percent in 2011 and 15.4 percent in 2010, it said. The percentage of top earners in 2011 who were women was 6.2 percent, compared to 6.7 percent in 2010, it said. The research on the Fortune 500 companies was 31 on data as of March 31, 2011. The slight changes in the numbers are not considered 32 significant, Catalyst said. Nevertheless, given the changes in U.S. politics, the future for women in business looks more 33 , said Ilene Lang, presidentand chief executive 34 of Catalyst. 'Overall we're 35 to see change next year,' Lang said. 'When we look at shareholders, decision makers, the general public, they're looking for change.' 'What they're basically saying is, 'Don't give us 36 of the status quo(现状). Get new ideas in there, get some fresh faces,'' she said. A．officer B．changes C．based D．positions E．more F．promising G．businesslike H．surveying I．essentially J．strides K．promotes L．statistically M．confused N．held O．expecting

单选题 Specialization can be seen as a response to the problem of an increasing accumulation of scientific knowledge. By splitting up the subject matter into smaller units, one man could continue to handle the information and use it as the basis for further research. But specialization was only one of a series of related developments in science affecting the process of communication. Another was the growing professionalization of scientific activity. No clear-cut distinction can be drawn between professionals and amateurs in science: exceptions can be found to any rule. Nevertheless, the word 'amateur' does carry a connotation that the person concerned is not fully integrated into the scientific community and, in particular, may not fully share its values. The growth of specialization in the nineteenth century, with its consequent requirement of a longer, more complex training, implied greater problems for amateur participation in science. The trend was naturally most obvious in those areas of science based especially on a mathematical or laboratory training, and can be illustrated in terms of the development of geology in the United Kingdom. A comparison of British geological publications over the last century and a half reveals not simply an increasing emphasis on the primacy of research, but also a changing definition of what constitutes an acceptable research paper. Thus, in the nineteenth century, local geological studies represented worthwhile research in their own right; but, in the twentieth century, local studies have increasingly become acceptable to professionals only if they incorporate, and reflect on, the wider geological picture. Amateurs, on the other hand, have continued to pursue local studies in the old way. The overall result has been to make entrance to professional geological journals harder for amateurs, a result that has been reinforced by the widespread introduction of refereeing, first by national journals in the nineteenth century and then by several local geological journals in the twentieth century. As a logical consequence of this development, separate journals have now appeared aimed mainly towards either professional or amateur readership. A rather similar process of differentiation has led to professional geologists coming together nationally within one or two specific societies, whereas the amateurs have tended either to remain in local societies or to come together nationally in a different way. Although the process of professionalization and specialization was already well under way in British geology during the nineteenth century, its full consequences were thus delayed until the twentieth century. In science generally, however, the nineteenth century must be reckoned as the crucial period for this change in the structure of science.