单项选择题

Californian Michael Schwabe said goodbye to the gas pump two years ago. He leased an electric car. Schwabe says he gets more out of driving an electric car than just a charge.
"With the price of gasoline and with the problems with clean air, it"s important we get electric vehicles out on the road."
On California roads there are about two thousand electric cars. By 2003, ten percent of all new cars may be required to have zero emissions. This is a mandate automakers say it is way ahead of its time.
Gloria Bergquist of the Alliance of Auto Manufacturers says, "The technology (for zero emissions) isn"t here yet; it still needs advancement in driving range to make it more appealing to a wider consumer audience."
Automakers blame it on the batteries. Power runs out on most cars after about 70 miles. However, some cars can now go more than 100 miles on a charge. Batteries are expensive. Carmakers say there is nothing they can do about it.
Tim Carmichael of the Clean Air Coalition says, "The automakers have not built a vehicle unless required to do so, so it"s very important for the state to stay committed to this program requiring automakers to build small amounts in beginning years and then the market will take off." Right now the California Air Resources Board requires that a percentage of new cars sold should be free of emissions. What is that percentage