剑桥雅思8-第三套试题-阅读部分-PASSAGE 1-阅读真题原文部分:
READING PASSAGE 1
You should spend about 20 minutes on Questions 1-13 which are bad on Reading Passage 1 below.
Striking Back at Lightning With Lars
Seldom is the weather more dramatic than when thunderstorms strike. Their electrical fury inflicts death or rious injury on around 500 people each year in the United States alone. As the clouds roll in, a leisurely round of golf can become a terrifying dice with death - out in the open, a lone golfer may be a lightning bolt's most inviting target. And there is damage to property too. Lightning damage costs American power companies more than $100 million a year.
But rearchers in the United States and Japan are planning to hit back. Already in laborat
和谐的英文ory trials they have tested strategies for neutralising the power of thunderstorms, and this winter they will brave real storms, equipped with an armoury of lars that they will be pointing towards the heavens to discharge thunderclouds before lightning can strike.
The idea of forcing storm clouds to discharge their lightning on command is not new. In the early 1960s, rearchers tried firing rockets trailing wires into thunderclouds to t up an easy discharge path for the huge electric charges that the clouds generate. The technique survives to this day at a test site in Florida run by the University of Florida, with support from the Electrical Power Rearch Institute (EPRI), bad in California. EPRI, which is funded by power companies, is looking at ways to protect the United States' power grid from lightning strikes. 'We can cau the lightning to strike where we want it to using rockets, ' says Ralph Bernstein, manager of lightning projects at EPRI. The rocket site is providing preci measurements of lightning voltages and allowing engineers to check how electrical equipment bears up.
Bad behaviour
But while rockets are fine for rearch, they cannot provide the protection from lightning strikes that everyone is looking for. The rockets cost around $1, 200 each, can only be fired at a limited frequency and their failure rate is about 40 per cent. And even when they do trigger lightning, things still do not always go according to plan. 'Lightning is not perfectly well behaved, ' says Bernstein. 'Occasionally, it will take a branch and go someplace it wasn't suppod to go. '精美图片头像
And anyway, who would want to fire streams of rockets in a populated area? 'What goes up must come down, ' points out Jean-Claude Diels of the University of New Mexico. Diels is leading a project, which is backed by EPRI, to try to u lars to discharge lightning safely - and safety is a basic requirement since no one wants to put themlves or their expensive equipment at risk. With around $500, 000 invested so far, a promising system is just emerging from the laboratory.
The idea began some 20 years ago, when high-powered lars were revealing their ability to extract electrons out of atoms and create ions. If a lar could generate a line of
ionisation in the air all the way up to a storm cloud, this conducting path could be ud to guide lightning to Earth, before the electric field becomes strong enough to break down the air in an uncontrollable surge. To stop the lar itlf being struck, it would not be pointed straight at the clouds. Instead it would be directed at a mirror, and from there into the sky. The mirror would be protected by placing lightning conductors clo by. Ideally, the cloud-zapper (gun)would be cheap enough to be installed around all key power installations, and portable enough to be taken to international sporting events to beam up at brewing storm clouds.
心碎离开
高三二轮复习计划 A stumbling block
However, there is still a big stumbling block. The lar is no nifty portable: it's a monster that takes up a whole room. Diels is trying to cut down the size and says that a lar around the size of a small table is in the offing. He plans to test this more manageable system on live thunderclouds next summer.
女性左腹部肋下隐痛 Bernstein says that Diels's system is attracting lots of interest from the power companie
搜狗招聘
对母校的祝福s. But they have not yet come up with the $5 million that EPRI says will be needed to develop a commercial system, by making the lars yet smaller and cheaper. 'I cannot say I have money yet, but I'm working on it, ' says Bernstein. He reckons that the forthcoming field tests will be the turning point - and he's hoping for good news. Bernstein predicts 'an avalanche of interest and support' if all goes well. He expects to e cloud-zappers eventually costing 100, 000 each.
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