2011年大学英语六级考试时间为6月18日，在备考六级时，很多考生都不会忘记考试的历年真题，下面我们为大家收集整理了历年的考试真题及参考答案，供大家参考。本文为：2007年12月大学英语六级考试真题及答案。
Part I Writing （30 minutes）
Directions: For this part, you are allowed 30 minutes to write a short essay entitled Digital Age. You should write at least 150 words following the outline given below.
1. 如今数字化产品得到越来越广泛的使用，并举例
2. 数字化产品的使用对人工作，学习，生活产生的影响
Digital part, you will have 15 minutes to go over the passage quickly and answer the questions on Answer Sheet 1.
For questions 1-7, choose the best answer from the four choices marked [A], [B], [C] and [D].
For questions 8 -10, complete the sentences with the information given in the passage.
Seven Ways to Save the World
Forget the old idea that conserving energy is a form of self-denial — riding bicycles, dimming the lights, and taking fewer showers. These days conservation is all about efficiency: getting the same — or better — results from just a fraction of the energy. When a slump in business travel forced Ulrich Rǒmer to cut cost costs at his family-owned hotel in Germany, he replaced hundreds of the hotel’s wasteful light bulbs, getting the same light for 80 percent less power. He bought a new water boiler with a digitally controlled pump, and wrapped insulation around the pipes. Spending about � 100,000 on these and other improvements, he slashed his � 90,000 fuel and power bill by � 60,000. As a bonus, the hotel’s lower energy needs have reduced its annual carbon emissions by more than 200 metric tons. “For us, saving energy has been very, very profitable,” he says. “And most importantly, we’re not giving up a single comfort for our guests.”
Efficiency is also a great way to lower carbon emissions and help slow global warming. But the best argument for efficiency is its cost — or, more precisely, its profitability. That’s because quickly growing energy demand requires immense investment in new supply, not to mention the drain of rising energy prices.
No wonder efficiency has moved to the top of the political agenda. On Jan. 10, the European Union unveiled a plan to cut energy use across the continent by 20 percent by 2020. Last March, China imposed a 20 percent increase in energy efficiency by 2020. Even George W. Bush, the Texas oilman, is expected to talk about energy conversation in his State of the Union speech this week.
The good news is that the world is full of proven, cheap ways to save energy. Here are the seven that could have the biggest impact:
Insulate
Space heating and cooling eats up 36 percent of all the world’s energy. There’s virtually no limit to how much of that can be saved, as prototype “zero-energy homes” in Switzerland and Germany have shown. There’s been a surge in new ways of keeping heat in and cold out (or vice versa). The most advanced insulation follows the law of increasing returns: if you add enough, you can scale down or even eliminate heating and air-conditioning equipment, lowering costs even before you start saving on utility bills. Studies have shown that green workplaces (ones that don’t constantly need to have the heat or air-conditioner running) have higher worker productivity and lower sick rates.
Change Bulbs
Lighting eats up 20 percent of the world’s electricity, or the equivalent of roughly 600,000 tons of coal a day. Forty percent of that powers old-fashioned incandescent light bulbs — a 19th-century technology that wastes most of the power it consumes on unwanted heat.
Compact fluorescent lamps, or CFLs, not only use 75 to 80 percent less electricity than incandescent bulbs to generate the same amount of light, but they also last 10 times longer. Phasing old bulbs out by 2030 would save the output of 650 power plants and avoid the release of 700 million tons of carbon into the atmosphere each year.
Comfort Zone
Water boilers, space heaters and air conditioners have been notoriously inefficient. The heat pump has altered that equation. It removes heat from the air outside or the ground below and uses it to supply heat to a building or its water supply. In the summer, the system can be reversed to cool building as well.
Most new residential buildings in Sweden are already heated with ground-source heat pumps. Such systems consume almost no conventional fuel at all. Several countries have used subsidies to jump-start the market, including Japan, where almost 1 million heat pumps have been installed in the past two years to heat water for showers and hot tubs.Remake Factories
From steel mills to paper factories, industry eats up about a third of the world’s energy. The opportunities to save are vast. In Ludwigshafen, German chemicals giant BASF runs an interconnected complex of more than 200 chemical factories, where heat produced by one chemical process is used to power the next. At the Ludwigshafen site alone, such recycling of heat and energy saves the company � 200 million a year and almost half its CO2 emissions. Now BASF is doing the same for new plants in China. “Optimizing (优化) energy efficiency is a decisive competitive advantage, ” says BASF CEO Jǔrgen Hambrecht.Green Driving
A quarter of the world’s energy — including two thirds of the annual production of oil — is used for transportation. Some savings come free of charge: you can boost fuel efficiency by 6 percent simply by keeping your car’s tires properly inflated (充气). Gasoline-electric hybrid (混合型) models like the Toyota Prius improve mileage by a further 20 percent over conventional models.
A Better Fridge
More than half of all residential power goes into running household appliances，producing a fifth of the world’s carbon emissions. And that’s true even though manufacturers have already hiked the efficiency of refrigerators and other white goods by as much as 70 percent since the 1980s. According to an International Energy Agency study, if consumers chose those models that would save them the most money over the life of the appliance, they’d cut global residential power consumption and their utility bills by 43 percent.
Flexible Payment
Who says you have to pay for all your conservation investment？“Energy service contractors” will pay for retrofitting (翻折改造) in return for a share of the client’s annual utility-bill savings. In Beijing, Shenwu Thermal Energy Technology Co. specializes in retrofitting China’s steel furnaces. Shenwu puts up the initial investment to install a heat exchanger that preheats the air going into the furnace，slashing the client’s fuel costs . Shenwu pockets a cut of those savings, so both Shenwu and the client profit.
If saving energy is so easy and profitable, why isn’t everyone doing it? It has to do with psychology and a lack of information. Most of us tend to look at today’s price tag more than tomorrow’s potential savings. That holds double for the landlord or developer, who won’t actually see a penny of the savings his investment in better insulation or a better heating system might generate. In many people’s minds, conservation is still associated with self-denial. Many environmentalists still push that view.