单选题 Soon after starting his job as supervisor of the Memphis, Tenn., public schools, Kriner Cash ordered an assessment of his new district's 104,000 students. What most concerned him was that the number of students considered 'highly mobile,' meaning they had moved at least once during the school year, had ballooned to 34,000. At least 1,500 students were homeless—probably more. It led him to think over an unusual suggestion: What if the best way to help kids in poverty-stricken urban neighborhoods is to get them out? Cash is now calling for Memphis to create a residential school for 300 to 400 kids whose parents are in financial distress. His proposal is at the forefront (最前线) of a broader national trend. Public boarding schools are hardly a new concept. But publicly financing boarding schools for inner-city kids is a very different suggestion. If Cash's dream becomes a reality, it will probably look a lot like SEED (Schools for Educational Evolution and Development), whose 320 students live on campus five days a week. Perhaps the most provocative (引起争论的) aspect of Cash's proposal is to focus on students in grades 3 through 5. Homelessness is growing sharply among kids at that critical age, when much of their educational foundation is set, Cash says. His aim: to prevent illiteracy and clear other learning roadblocks early, so the problem 'won't migrate into middle and high school.' Students will remain on campus year-round. 'It sounds very exciting, but the devil is in the details,' says Ellen Bassuk, president of the National Center on Family Homelessness in Newton, Mass. 'What's it like to separate a third-or fifth-grader from their parents?' It may help to consider the experience of SEED student Mansur Muhammad, 17. When he arrived seven years ago, the first few weeks were tough. But Muhammad hasn't looked back. He maintains a 3.2 GPA and reshelves books in the school's library for $160 every couple of days, when he's not in his room listening to rap or classical music and writing poetry. Inspired by a teacher, Muhammad is working on a book. 'It was a long road for me to get here,' he says, 'and I have a long way to go.'

单选题 Directions: For this part, you are allowed 30 minutes to write an advertisement on your campus website to sell some of the course books you used at college. Your advertisement may include a brief description of their content, their condition and price and your contact information. You should write at least 120 words but no more than 180 words.

单选题 中国有着悠久的扇子文化。最早的扇子出现在3000年前，由羽毛制成。如今，扇子的制作材料已变得多样化，最常用的是纸和真丝。扇子的用途很广泛，除了能使人凉快之外，还可用于舞蹈、装饰等。在中国文化里，与其说扇子是个工具，不如说它是一个艺术品。扇面上的书法(calligraphy)、绘画和诗歌为扇子增添了艺术价值。使扇子为历代收藏家所珍爱。

单选题 Can Burglars Jam Your Wireless Security System? A. Any product that promises to protect your home deserves careful examination. So it isn't surprising that you'll find plenty of strong opinions about the potential vulnerabilities of popular home-security systems. B. The most likely type of burglary (入室盗窃) by far is the unsophisticated crime of opportunity, usually involving a broken window or some forced entry. According to the FBI, crimes like these accounted for roughly two-thirds of all household burglaries in the US in 2013. The wide majority of the rest were illegal, unforced entries that resulted from something like a window being left open. The odds of a criminal using technical means to bypass a security system are so small that the FBI doesn't even track those statistics. C. One of the main theoretical home-security concerns is whether or not a given system is vulnerable to being blocked from working altogether. With wired setups, the fear is that a burglar (入室盗窃) might be able to shut your system down simply by cutting the right cable. With a wireless setup, you stick battery-powered sensors up around your home that keep an eye on windows, doors, motion, and more. If they detect something wrong while the system is armed, they'll transmit a wireless alert signal to a base station that will then raise the alarm. That approach will eliminate most cord-cutting concerns—but what about their wireless equivalent, jamming? With the right device tuned to the right frequency, what's to stop a thief from jamming your setup and blocking that alert signal from ever reaching the base station? D. Jamming concerns are nothing new, and they're not unique to security systems. Any device that's built to receive a wireless signal at a specific frequency can be overwhelmed by a stronger signal coming in on the same frequency. For comparison, let's say you wanted to 'jam' a conversation between two people all you'd need to do is yell in the listener's ear. E. Security devices are required to list the frequencies they broadcast on—that means that a potential thief can find what they need to know with minimal Googling. They will, however, need to know what system they're looking for. If you have a sign in your yard declaring what setup you use, that'd point them in the right direction, though at that point, we're talking about a highly targeted, semi-sophisticated attack, and not the sort of forced-entry attack that makes up the majority of burglaries. It's easier to find and acquire jamming equipment for some frequencies than it is for others. F. Wireless security providers will often take steps to help combat the threat of jamming attacks. SimpliSafe, winner of our Editors' Choice distinction, utilizes a special system that's capable of separating incidental RF interference from targeted jamming attacks. When the system thinks it's being jammed, it'll notify you via push alert (推送警报). From there, it's up to you to sound the alarm manually. G. SimpliSafe was singled out in one recent article on jamming, complete with a video showing the entire system being effectively bypassed with handheld jamming equipment. After taking appropriate measures to contain the RF interference to our test lab, we tested the attack out for ourselves, and were able to verify that it's possible with the right equipment. However, we also verified that SimpliSafe's anti-jamming system works. It caught us in the act, sent an alert to my smartphone, and also listed our RF interference on the system's event log. The team behind the article and video in question make no mention of the system, or whether or not it detected them. H. We like the unique nature of that software. It means that a thief likely wouldn't be able to Google how the system works, then figure out a way around it. Even if they could, SimpliSafe claims that its system is always evolving, and that it varies slightly from system to system, which means there wouldn't be a universal magic formula for cracking it. Other systems also seem confident on the subject of jamming. The team at Frontpoint addresses the issue in a blog on its site, citing their own jam protection software and claiming that there aren't any documented cases of a successful jam attack since the company began offering wireless security sensors in the 1980s. I. Jamming attacks are absolutely possible. As said before, with the right equipment and the right knowhow, it's possible to jam any wireless transmission. But how probable is it that someone will successfully jam their way into your home and steal your stuff? J. Let's imagine that you live in a small home with a wireless security setup that offers a functional anti-jamming system. First, a thief is going to need to target your home, specifically. Then, he's going to need to know the technical details of your system and acquire the specific equipment necessary for jamming your specific setup. Presumably, you keep your doors locked at night and while you're away, so the thief will still need to break in. That means defeating the lock somehow, or breaking a window. He'll need to be jamming you at this point, as a broken window or opened door would normally release the alarm. So, too, would the motion detectors in your home, so the thief will need to continue jamming once he's inside and searching for things to steal. However, he'll need to do so without tripping the anti-jamming system, the details of which he almost certainly does not have access to. K. At the end of the day, these kinds of systems are primarily designed to protect against the sort of opportunistic smash-and-grab attack that makes up the majority of burglaries. They're also only a single layer in what should ideally be a many-sided approach to securing your home, one that includes common sense things like sound locks and proper exterior lighting at night. No system is impenetrable, and none can promise to eliminate the worst case completely. Every one of them has vulnerabilities that a knowledgeable thief could theoretically exploit. A good system is one that keeps that worst-case setting as improbable as possible while also offering strong protection in the event of a less-extraordinary attack.

单选题 Urbanization—migration away from the suburbs to the city center—will be the biggest real estate trend in 2015, according to a new report. The report says America's urbanization will continue to be the most significant issue affecting the industry, as cities across the country imitate the walkability and transit-oriented development making cities like New York and San Francisco so successful. As smaller cities copy the model of these '24-hour cities,' more affordable versions of these places will be created. The report refers to this as the coming of the '18-hour city,' and uses the term to refer to cities like Houston, Austin, Charlotte, and Nashville, which are 'positioning themselves as highly competitive, in terms of livability, employment offerings, and recreational and cultural facilities.' Another trend that looks significant in 2015 is that America's largest population group, Millennials (千禧一代), will continue to put off buying a house. Apartments will retain their appeal for a while for Millennials, haunted by what happened to home-owning parents. This trend will continue into the 2020s, the report projects. After that, survey respondents disagree over whether this generation will follow in their parents' footsteps, moving to the suburbs to raise families, or will choose to remain in the city center. Another issue affecting real estate in the coming year will be America's failing infrastructure. Most roads, bridges, transit, water systems, the electric grid, and communications networks were installed 50 to 100 years ago, and they are largely taken for granted until they fail. The report's writers state that America's failure to invest in infrastructure impacts not only the health of the real-estate market, but also our ability to remain globally competitive. Apart from the specific trends highlighted above, which cause some investors to worry, the report portrays an overall optimism borne by the recent healthy real-estate 'upcycle' and improving economy. Seventy-four percent of the respondents surveyed report a 'good to excellent' expectation of real-estate profitability in 2015. While excessive optimism can promote bad investment patterns, resulting in a real-estate 'bubble,' the report's writers downplay that potential outcome in that it has not yet occurred.

单选题 Money spent on advertising is money spent as well as any I know of. It serves directly to assist a rapid distribution of goods at reasonable prices, thereby establishing a firm home market and so making it possible to provide for export at competitive prices. By drawing attention to new ideas it helps enormously to raise standards of living. By helping to increase demand it ensures an increased need for labour, and is therefore an effective way to fight unemployment. It lowers the costs of many services: without advertisements your daily newspaper would cost four times as much, the price of your television license would need to be doubled, and travel by bus or tube would cost 20 percent more. And perhaps most important of all, advertising provides a guarantee of reasonable value in the products and services you buy. Apart from the fact that twenty-seven Acts of Parliament govern the terms of advertising, no regular advertiser dare promote a product that fails to live up to the promise of his advertisements. He might fool some people for a little while through misleading advertising. He will not do so for long, for mercifully the public has the good sense not to buy the inferior article more than once. If you see an article consistently advertised, it is the surest proof I know that the article does what is claimed for it, and that it represents good value. Advertising does more for the material benefit of the community than any other force I can think of. There is one more point I feel I ought to touch on. Recently I heard a well-known television personality declared that he was against advertising because it persuades rather than informs. He was drawing excessively fine distinctions. Of course advertising seeks to persuade. If its message was confined merely to information—and that in itself would be difficult if not impossible to achieve, for even a detail such as the choice of the colour of a shirt is subtly persuasive—advertising would be so boring that no one would pay any attention to. But perhaps that is what the well-known television personality wants.