Traffic Management Traffic lights are key tools for regulating traffic How.They are not, however, perfect.Drivers exchange the traffic jams that would happen at unmanaged crossings for a pattern of stop-go movement that can still be annoying, and which bums more fuel than a smooth passage would. Creating such a smooth passage means adjusting a vehicle's speed so that it always arrives at the lights when they are green.That is theoretically possible, but practically hard.Roadside signs wired to traffic lights can help get the message across a couple hundred metres from a crossing, but such signs are expensive, and are not widespread.Margaret Martonosi and Emmanouil Koukoumidis at Princeton University, and Li-Shiuan Peh at the Massachusetts Institute of Technology, however, have an idea that could make the process cheaper and more effective.Instead of a hardwired network of signs, they propose to use mobile-phone applications. For a driver to benefit, lie must load the team's software , named SignalGuru, into his phone and then put it on a special thing attached to the inside of his car's windscreen, with the camera lens pointing forward.SignalGuru is designed to detect traffic lights and track their status as red, yellow or green.It broadcasts this information to other phones in the area that are fitted with the same software, and --if there are enough of them ?the phones thus each know the status of most of the lights around town.Using this information, SignalGuru is able to calculate the traffic-light schedule for the area and suggest the speed at which a driver should travel in order to avoid red lights. Tests in Cambridge, Massachusetts, where five drivers were asked to follow the same route for three hours, and in Singapore, where eight drivers were asked to follow one of two routes for 30 minutes, revealed that SignalGuru was capable of predicting traffic-light activity with an accuracy of 98.2% and 96.3% respectively, in the two cities.This was particularly impressive because in Cambridge the lights... SignalGuru is an application used on _ . A) a camera B) a computer C) a mobile phone D) a GPS system in one's car
C
(Question)
As goods and services improved, people were persuaded to spend their money on changing from old to new, and found the change worth the expense. When an airline equipped itself with jets, for example, its costs (and therefore air fare) would go up, but the new planes meant such an improvement that the higher cost was justified. A new car (or wireless, washing machine, electric kettle) made life so much more comfortable than the old one that the high cost of replacement was fully repaid. Manufacturers still cry their goods as persuasively as ever, but are the improvements really worth paying for? In many fields, things have now reached such a high standard of performance that further progress is very limited and very, very expensive. Airlines, for example, go to enormous expense in buying the latest jets , in which vast research costs have been spent on ly small improvements. If we abandon these vast costs we might lose the chance of cutting minutes away from flying times; but wouldn't it be better to see airfares drop dramatically, as capital costs become ly insignificant? Again, in the context of a 70 m. p. h. Limit, with lines of cars traveling so close as to control each other's speeds, improvements in performance are actually irrelevant; improvements in handling are unnecessary, as most production cars grip the road perfectly, and comfort has now reached a very high level. Small improvements here are unlikely to be worth the thousands that anybody replacing an ordinary family car every two years may have spent on them. Let us instead have cars -- or wireless, electric kettles, washing machines, television sets -- which are made to last, and not to be replaced. Significant progress is obviously a good thing, but the insignificant progression from model-change to model-change is not. The author is obviously challenging the social norm that _ . A) it is important to improve goods and services B) development of technology makes our life more comfortable C) it is reasonable that prices are going up all the time D) slightly improved new products are worth buying
(Answer)
D
Looking for a new weight loss plan? Try living on top of a mountain. Mountain air contains less oxygen than air at lower altitudes, so breathing it causes the heart to beat faster and the body to burn more energy. A handful of studies have found that athletes training at high altitudes tend to lose weight. Doctor Florian Lippl of the University Hospital Of Ludwig-Maximilians-university Munich wondered how the mountain air would affect overweight individuals if they weren't doing any more physical activity than usual. Lippl and his colleagues invited 20 overweight men to an environmental research station about 300 meters below the summit of Zugspitze, a mountain around 2,970 meters near the Austrian border. They were allowed to eat as much as they liked. The men also gave blood so that researchers could test for hormones linked to appetite and fatness. At the end of the week, the men, whose mean weight starting out was 105kg, had lost on average about l.5kg. The men's blood pressure also dropped, which the researchers believed was due to weight lost. Exactly what caused the weight loss is uncertain. Loss of appetite is common at higher altitudes, and indeed the men ate significantly less than usual--about 700 calories fewer per day. Lippl also notes that because their consumption was being recorded, they may have been more self-conscious about what they ate. Regardless, eating less accounts for just l kg of the l.5 kg lost, says Lippl. He thinks the increased metabolic rate, which was measured, also contributed to weight loss but cannot separate the different effects with the given data. Appetite loss at high altitudes could certainly be key, notes Damian Bailey, a physiologist at the University of Glamorgan, UK, who recently lost 11 kg during a 3-month expedition to the Andes in Chile. Unfortunately, for the average person there is no treatment that can resemble living at high altitude, says Lippl. The only alternative is hypobaric chamber, which exposes subjects to low oxygen and isn't practical as a... In what manner does Lippl talk about the way of losing weight by spending holidays on mountains? A) casual B) inaccurate C) uncertain D) confident
A