5．
Fuel Cell Technology for Cars
Fill her up with hydrogen？That's what someCalifornia motorists may be saying soon，as car makers tryto speed up production of zero emission（零排放） cars to meet state requirements in the near future．
Beneath the skin of this ordinary looking Hondas FCX Concept Vehicle sits an electro-chemical reactor：a hand built，astronomically expensive power plant known as a fuel cell．It's expected to be running ordinary family cars on California's roads within three years．
So what exactly is a fuel cell，anyway？Why are governments，private businesses and academic institutions cooperating to develop and produce them？A fuel cell，very simply described，is a power generator，making electricity through the combination of hydrogen and oxygen．Fuel cells generate electrical power quietly and efficiently，without pollution，Unlike power sources that use fossil fuels，the only by-products from an operating fuel cell are heat and water．To be more technical about it，a hydrogen atom with its one electron，attempts to pass through a fuel cell membrane（膜） to unite with an oxygen atom．The membrane allows only the hydrogen proton（質(zhì)子） to pass through，forcing its electron to run around the membrane to catch up with the proton on the other side．This creates electricity，water，and heat，but no exhaust emissions．
If the fuel cell is powered with pure hydrogen，it has the potential to be up t0 80-percent efficient，That is，it turns 80percent of the energy content of the hydrogen into electrical energy．However，we still need to turn the electrical energy into mechanical work．This is accomplished by the electric motor．A reasonable number for the efficiency of the motor is about 80percent．So we have 80-percent efficiency in generating electricity，and 80-percent efficiency turning it into mechanical power．That gives an overall efficiency of about64percent．Honda's FCX concept vehicle reportedly has 60-percent energy efficiency，which is twice or even three times more efficient than usual cars．
But in spite of all the advantages described above，experts say，"We still have technical challenges getting this extremely complex system to work properly，the way customers expect it to work．There are challenges in using new fuels，and providing the new fuel basic facilities．And before fuel cell vehicles hit the road，there will have to be a network of hydrogen stations that will allow drivers to fill up with the flammable gas，under 36-hundred pounds of pressure．"
61．What can be inferred from California's"zero emissions policy"？C
A．New cars with fuel cell technology will surely become much cheaper．
B．By carrying out the policy，traffic will not be so busy as it is now．
C．The quality of life in California will improve once this policy is in effect．
D．With facilities of new kinds，more local employment will be created．
62．What does the phrase"power plant"refer to？A
A．A power device generating electricity．
B．A power station providing electricity．
C．A power component consuming electricity．
D．A power engine using electricity．
63．One of the reasons why fuel cell powered vehicles are superior is that．C
A．they give out almost no water or heat
B．they run faster and more smoothly
C．they give out almost no noise
D．they turn 64% of the energy into electricity
64．What does the author want to tell us in the last paragraph？D
A．Customers will not think it a good idea to develop fuel cell technology．
B．It is still not very easy to speed up production of zero emission cars．
C．We can't ignore the financial problems to build a network of hydrogen stations．
D．We still have much difficulty turning all the chains of the business into reality．
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