职称英语理工类试题

[商务英语专业大学排名]全国共有25所开设了商务英语专业的大学参与了排名，其中排名第一的是对外经济贸易大学，排名第二的是中南财经政法大学，排名第三的是西南财经大学，以下是商务英语专业大学排名列表...+阅读

Sugar Power for Cell PhonesUsing enzymes monly found in living cells，a new type of fuel cell produces small amounts of electricity from sugar.If the technology is able to succeed in mass production，you may some day share your sweet drinks with your cell phone.In fuel cells，chemical reactions generate electrical currents.The process usually relies on precious metals，such as platinum.In living cells，enzymes perform a similar job，breaking down sugars to obtain electrons and produce energy.When researchers previously used enzymes in fuel cells，they had trouble keeping them active，says Shelley D.Minteer of St Louis University1.Whereas biological cells continually produce fresh enzymes，theres no mechanism in fuel cells to replace enzymes as they quickly degrade.Minteer and Tamara Klotzbach，also of St Louis University，he now developed polymers that wrap around an enzyme and preserve it in a microscopic pocket.We tailor these pockets to provide the ideal microenvironment for the enzyme，Minteer says.The polymers keep the enzyme active for months instead of days.In the new fuel Cell，tiny polymer bags of enzyme are embedded in a membrane that coats one of the electrodes.When glucose from a sugary liquid gets into a pocket，the enzyme oxidizes it，releasing electrons and protons.The electrons cross the membrane and enter a wire through which they trel to the other electrode，where they react with.oxygen in the atmosphere to produce water.The flow of electrons through the wire constitutes an electrical current that can generate power.So far，the new fuel cells dont produce much power，but the fact that they work at all is exciting，says Paul Kenis，a chemical engineer at the University of Illinois2 at Urhana-Champaign3.Just getting it to work. Kenis says，is a major acplishment.Sugar-eating fuel cells could be an efficient way to make electricity.Sugar is easy to find. And the new fuel cells that run on it are biodegradable，so the technology wouldnt hurt the environment.The scientists are now trying to use different enzymes that will get more power from sugar.They predict that popular products may be using the new technology in as little as 3 years.1. According to the first paragraph，when can we share our sweet drinks with our cell phones?A When enzymes can be monly found in living ceils.B When the technology of producing a new type of fuel cell appears.C When the technology of a new type of fuel cell is suitable for mass production.D When the technology of mass producing cell phones appears.2. What trouble did Minteer and Klotzhach he in their research?