【听力原文】
[16 ] Are electric cars the way of the future? Automobile manufacturers are under pressure to develop cars that do not pollute. One powerful motive is a California law requiring that by the year 2010 ten percent of new car sales in the state be so-called zero-emission vehicles. These cars must put no pollutants whatsoever into the atmosphere. California is a huge market for the automobile companies, so they are working hard to meet these standards.[17 ] So far the electric ear seems to be the best alternative. So the big advantage of electric cars is that they don't pollute. However, they will be in competition with gas-powered cars and that's where the weaknesses come out. The big problem is that the batteries that power electric cars weigh a lot relative to the amount of power they deliver. For instance, in one prototype electric car, [ 18 ] the batteries weighed 400 kilograms. And they provide enough energy to go 250 kilometers before recharging, which takes eight hours. Compare that to a moderately fuel-efficient conventional car, it can go 600 to 700 kilometers on a tank of gas and refilling takes just minutes. If there are other drains on an electric car’s batteries besides the motor, headlights, air- conditioning or a heater, its already limited range will be significantly reduced. So automobile engineers are trying to make more powerful batteries that would increase the cars' range and make them more attractive to buyers.
What is the talk mainly about?
【解题思路】四项均为名词短语，分别为电动汽车、提高燃料效率、加利福尼亚州的污染法规、汽车安全，相互之间的关联度不高，加之本题为该短文的第一题，因此很有可能考查短文主题。
【解析】短文开头开门见山，直入主题： “Are electric cars the way of the future?(电动车会成为未来的主流交通工具吗?)”如果听到此句时没有抓住主题，后面还有机会，因为整篇文章就是围绕electric cars的优势和劣势展开的。故选A。