Ausubel of Rockefeller University in New York, US. says the key renewable energy sources, including sun, wind and biofuels, would all require vast 1 of land if developed up to large scale production 1 – unlike nuclear power. That land would be far better left alone 2 , he says. Renewables look attractive when they are quite 2 . But if we start producing renewable energy on a large scale, the fallout is going to be horrible. Instead, Ausubel argues 3 renewed development of nuclear. Ausubel draws his conclusions by analysing the amount of energy renewables, natural gas and nuclear can produce in terms of power per square metre of land used 3 . Moreover, he claims that as renewable energy use increases, this measure of efficiency 4 will 4 as the best land for wind, biofuels, and solar power gets used up. Using biofuels to obtain the 5 amount of energy as a 1000 megawatt nuclear power plant would require 2500 square kilometres of farm 6 , Ausubel says. 'We should be sparing land for nature 5 , not using it as pasture for cars and trucks,' he adds. Solar power is much more efficient than biofuel in terms of the area of land 7 , but it would still require 150 square kilometres of photovoltaic cells to 8 the energy production of the 1000 MW nuclear plant. In another example, he says meeting the 2005 US electricity demand via wind power alone would need 780,000 square kilometres, an area the size of Texas. However, several experts are highly critical 9 Ausubel’s conclusions. John Turner of the US government’s National Renewable Energy Laboratory says that 10 the US got all of its power from solar energy, it would still need less than half the amount of land that has been paved over for highways. Further, it need not 11 additional land. The US could get a quarter of its energy just from covering rooftops of 12 buildings, he says. According to Turner, the same 'dual use' also applies to wind power 6 . 'The footprint for wind 7 is only 5% of the land that it 13 . Farmers can still farm the land that the turbines are on 8 . Turner says looking solely at land use is an oversimplification of the 14 . 'I’m not sure I’d want to build one of these nuclear plants in Afghanistan 9 , but we could 15 put in wind and solar power,' he adds. 小题1:A. figures       B. amounts          C, unmbers        D. digits 小题2: A．small B．huge C．little D．vast 小题3: A．at B．over C．for D．against 小题4: A．expand B．minimize C．enlarge D．decrease 小题5: A．same B．similar C．alike D．identical 小题6: A．region B．site C．area D．land 小题7: A．leased B．cultivated C．used D．purchased 小题8: A．patch B．match C．catch D．fetch 小题9: A．in B．with C．of D．on 小题10: A．even if B．only if C．what if D．as if 小题11: A．lock up B．take up C．give up D．set up 小题12: A．towering B．interesting C．nice-looking D．existing 小题13: A．surrounds B．contains C．includes D．covers 小题14: A．issue B．stuff C．summary D．suggestion 小题15: A．doubtfully B．supposedly C．certainly D．honestly