Electric cars are dirty. In fact, not only are they dirty, they might even be more dirty than their gasoline-powered cousins. People in California love to talk about “zero-emissions（排放）vehicles”, but people in California seem to be clueless about where electricity comes from. Power plants most all use fire to make it. Apart from the few people who have their roofs covered with solar cells, we get our electricity from generators（发电机）. Generators are fueled by something--usually coal, oil, but also by heat generated in nuclear power plants. There are a few wind farms and geothermal（地热） plants as well, but by far we get electricity mainly by burning something. In other words, those 'zero-emissions' cars are likely coal-burning cars. Because the coal is burned somewhere else, it looks clean. It is not true. It's as if the California Greens are covering their eyes—“If I can't see it, it's not happening.”  Gasoline is an incredibly efficient way to power a vehicle; a gallon of gas has a lot of energy in it. But when you take that gas（or another fuel）and first use it to make electricity, you waste a nice part of that energy, mostly in the form of wasted heat--at the generator, through the transmission lines, etc. A gallon of gas may drive your car 25 miles. But the electricity you get from that gallon of gas won't get you nearly as far -- so electric cars burn more fuel than gasoline-powered ones. If our electricity came mostly from wind or geothermal, or solar, then an electric car truly would be clean. But for political, technical, and economic reasons, we don't use much of those energy sources. In addition, electric cars' batteries which are poisonous for a long time will eventually end up in a landfill. And finally, when cars are the polluters, the pollution is spread across all the roads. When it's a power plant, though，all the junk is in one place. Nature is very good at cleaning up when things are not too concentrated, but it takes a lot longer when all the garbage is in one spot. 小题1:What’s the main idea of the passages? A．Electric cars aren’t actually clean. B．Electric cars are zero-emissions vehicles. C．Zero-emissions vehicles are popular. D．Gasoline-powered cars are more efficient. 小题2:Which of the following words can replace “be clueless about” in Paragraph 2? A．Be familiar with． B．Be curious about． C．Fail to understand． D．Show their interest in． 小题3:The electricity we get from a gallon of gas may make our car run _________. A．at least 25 miles B．more than 25 miles C．as far as 25 miles D．less than 25 miles 小题4:In the author’s opinion, compared with cars using gas, electric cars are more __________. A．environmentally-friendly B．expensive C．efficient D．harmful 小题5:It can be inferred from the passage that __________. A．electric cars' batteries are poisonous for a long time B．now electric cars are used more than their gasoline-powered cousins C．zero-emissions vehicles should be chosen to protect our environment D．electric cars are not clean in that we get electricity mainly by burning something