【正确答案】Cambridge University professors have just overcome the technical difficulties in the development of lithium air battery. Theoretically, only this battery allows electric vehicles be comparable to gasoline and diesel vehicles in the mileage without having to carry huge and bulky battery pack. If the technology can be converted from the product in the laboratory into a commodity, people can drive from London to Edinburgh with one charge while the cost and weight of the battery is only one-fifth of today’ s electric vehicles with lithium batteries.