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Global energy demand is expected to triple by mid-century. The earth is unlikely to run out of fossil fuels by then, given its vast reserves of coal, but it seems unthinkable that we will continue to use them as we do now. It’s not just a question of supply and price, or even of the disease caused by filthy air. The terrorist assault on the World Trade Center raises other scary scenarios: how much easier would it be to crack open the Trans-Alaska pipeline and how much deadlier would it be to bomb a nuclear plant than to attack a wind armSkeptics may recall the burst of enthusiasm for conservation and renewable power when oil prices quadrupled in the 1970s. State-funded energy research and development surged, while tax incentives boosted solar, wind and other alternatives to petroleum and the atom. But when oil supplies loosened and prices dropped in the early 1990s, governments lost interest. In the state of California, subsidies evaporated, pushing wind companies into bankruptcy.Clean energy has long way to go. Only 2.2% of the world’s energy comes from "new" renewables such as small hydroelectric dams, wind, solar and geothermal. How to boost that share--and at what pace--is debated in industrialized nations--from Japan, which imports 99.7 % of its oil, to Germany, where the nearby Chernobyl accident turned the public against nuclear plants, to the U.S., where the Bush Administration has strong ties to the oil industry. But the momentum toward clean renewables is undeniable. How soon we reach an era of clean, inexhaustible energy depends on technology. Solar and wind energies are intermittent: When the sky is cloudy or the breeze dies down, fossil fuel or nuclear plants must kick into compensate. But scientists are working on better ways to store electricity from renewable sources.While developed nations debate how to fuel their power plants, however, some 1.6 billion people--a quarter of the globe’s population--have no access to electricity or gasoline. Many spend their days collecting firewood and cow dung, burning it in primitive stoves that belch smoke into their lungs. To emerge from poverty, they need modern energy. And renewables can help. From village-scale hydropower to household photovoltaic systems to bio-gas stoves that convert dung into fuel.Ultimately, the earth can meet its energy needs without fouling the environment. "But it won’t happen," asserts Thomas Johansson, an energy adviser to the United Nations Development Program, "without political will." To begin with, widespread government subsidies for fossil fuels and nuclear energy must be dismantled to level the playing field for renewables. Moreover, government should pressure utility to meet targets for renewable sources of energy. The author’s biggest worry about using nuclear energy is that （）
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For the first time, stem cells purified from fat have been used to heal an injury in a living animal. Michael Longaker of Stanford University in California and his team showed in mouse experiments that so-called adipose derived adult stromal (ADAS) cells purified from a rodent’s belly fat could be coaxed to heal a skull fracture too large to mend by itself.The power of ADAS cells to transform into bone, cartilage and even neurons has been studied for years in test tubes. But Jeffrey Gimble, who studies human ADAS cells at Louisiana State University in Baton Rouge says Longaker’s report is an important step forward. "Actually repairing a defect in an animal model had never been done. This is an excellent study." If the same technique works in humans, these cells could be coaxed to mend broken bones and correct other defects in tens of thousands of surgical procedures each year in which bone grafts and prosthetics are now necessary.Longaker’s group tested the ability of ADAS cells to heal four-millimetre-long fractures surgically-induced in the skulls of mice. In 12 weeks, the cells filled 70 to 90 per cent of the defects, while untreated animals had only unorganized bone formation in less than 10 per cent of the fractures. No extreme genetic manipulation or treatment of the cells was necessary. ADAS cells began manufacturing bone when they were simply laid onto a biodegradable polymer that contained apatite, a compound that naturally occurs in bone. Furthermore, the ADAS cells performed as well as bone marrow stromal cells, which would seem to be more natural architects of bone. It remains to be seen whether human ADAS cells will build bone as effectively. But researchers are excited about the prospects. Human bone marrow stromal cells are already being used in clinical trials as sources of skeleton-building material, but the ADAS cells may have some significant advantages.Longaker reports that ADAS cells grow seven times faster than the bone marrow cells in the laboratory. And it is relatively easy to harvest more than a litre of fat tissue, even from patients who are not obese. Bone marrow is much less plentiful and must be removed in a painful surgical procedure. Of course, liposuction itself is not a pleasant operation. But according to the American Society of Plastic Surgeons, more than 300,000 people volunteered to have the procedure in 2003 simply for cosmetic reasons. "If the procedure was the first step to healing broken bones or replacing other tissue its popularity could only grow," says Gimble. "Just think of that.\ Gimble speaks highly of Longaker in that （）
国务院总理温家宝2010年5月5日主持召开国务院常务会议，审议并通过《国家中长期教育改革和发展规划纲要(2010～2020年)》。 会议指出，未来十年是我国实施现代化建设“三步走”战略的关键阶段。制定并实施《国家中长期教育改革和发展规划纲要(2010～2020年)》，在新的历史起点上加快推进教育改革和发展，对于建设人力资源强国、满足群众接受良好教育的需求、全面建成惠及十几亿人口的小康社会具有重大战略意义。 请回答以下问题： 《教育规划纲要》指出，未来十年教育的工作方针是( )。
在窗体上利用菜单编辑器设计一个主菜单项“菜单控制”(Name属性值为mnuMenu)，然后为其设计两个子菜单项“增加菜单”(Name属性值为mnuAdd) 和“减少菜单”(Name属性值为mnuDel)，另外设置一个标题为空的菜单项 Dim Inxld As Integer Private Sub mnuAdd_Click() Dim mnuc As String mnuc=InputBox("input caption") InxId；InxId+1 【6】 mnuDyn(InxId) mnuDyn(Inxld) ，Calption=mnuc mauDyn(InxId) .Visible=True End Sub Private SubmnuDel_Click() Dim i As Integer If 【7】 Then MsgBox "菜单项已全部被删除" Else Unload mnuDyn(InxId) InxId=InxId-1 End If End Sub
Paper is different from other waste produce because it comes from a sustainable resource: trees. (21) the minerals and oil used to make plastics and metals, trees are (22) . Paper is also biodegradable, so it does not pose as much threat to the environment when it is discarded. (23) 45 out of every 100 tonnes of wood fibre used to make paper in Australia comes from waste paper, the rest comes directly from virgin fibre from forests and plantations. By world standards this is a good (24) since the world-wide average is 33 percent waste paper. Governments have encouraged waste paper collection and (25) schemes and at the same time, the paper industry has responded by developing new recycling technologies that have (26) even greater utilization of used fibre. (27) , industry’s use of recycled fibres is expected to increase at twice the rate of virgin fibre over the coming years.Already, waste paper (28) 70% of paper used for packaging and advances in the technology (29) to remove ink from the paper have allowed a higher recycled (30) in newsprint and writing paper. To achieve the benefits of recycling, the community must also (31) . We need to accept a change in the quality of paper products; (32) stationery may be less white and (33) a rougher texture. There also needs to be (34) from the community for waste paper collection programs. Not only do we need to make the paper (35) to collectors but it also needs to be separated into different types and sorted from contaminants such as staples, paperclips, string and other miscellaneous (36) .There are technical (37) to the amount of paper which can be recycled and some paper products cannot be collected for reuse. These include paper (38) books and permanent records, photographic paper and paper which is badly contaminated. The four most common (39) of paper for recycling are factories and retail stores which gather large amounts of packaging material (40) goods are delivered, also offices which have unwanted business documents and computer output, paper converters and printers and lastly households which discard newspapers and packaging material. The paper manufacturer pays a price for the paper and may also incur the collection cost. 28（）
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