問題詳情


(B)It's supposed to make computers small enough to implant into a wrist and supply materials that strengthen and lighten bridges and airplanes. It might even cure cancer. But some environmentalists fear that nanotechnology, the fast-advancing sci­ence of manipulating materials at the molecular scale, may create contam­inants whose tiny size makes them ultra-hazardous.     “If they get in the bloodstreams or into ground water, even if the nanoparticles themselves aren’t dangerous, they could react with other things that are harmful,” said Kathy Jo Wetter, a researcher with the ETC Group, an environmental organization that also opposes genetically modified crops.     In a move that researchers believe is too dramatic, ETC is asking governments to halt development of nanotechnology until environmental and health concerns are researched and assuaged.    Scientists say fears such as ETC consist mainly of speculation. Nanotechnology, they say,involves well-known materials such as carbon, zinc and gold — both toxic and benign. New tools simply let researchers alter those materials at the atomic level, where the particles are measured in nanometers, or billionths of a meter.    “It may have some unexpected consequences. Some could be toxic,” said Mihail Roco, the National Science Foundation’s senior adviser on nanotechnology. “But this happens with larger particles and in other industries. The risks are very small in comparison with the benefits.”    Nanotechnology research is one of the US government’s top science initiatives, fed by US$604 million in federal funds this year. ETC estimates worldwide research funding at US$4 billion, including government initiatives in Japan, Taiwan, South Korea and Australia.    The ETC, whose Canada-based group organized discussion at the UN World Summit on Sustainable Development in early September in South Africa, believes the coming industrial production of nanoparticles has not been properly scrutinized for environmental or health risks.    Wetter wonders what will happen if the tiny, man-made particles accumulate in the liver or lungs? Carbon nanotube molecules currently touted as a substitute for silicon in even tinier transistors closely resemble spiky asbestos fibers, she said. Although a pair of studies on mice and guinea pigs indicated that the carbon fibers probably posed little risk to humans, Wetter and other environmentalists speculate they could damage human’s lungs.
41. Scientists think the fear of ETC just comes from ____________.
(A) the facts
(B) clinical experience
(C) speculation
(D) broadcast

參考答案

答案：C
難度：適中0.4375
統計：A(2),B(4),C(7),D(2),E(0)

內容推薦

內容推薦