An electric car is on display with a note indicating its oil-free mileage during an event to mark the National Plug In Day at the Capitol Hill, in Washington D.C., Sept. 29, 2013. The National Plug In Day is a nationwide celebration to heighten awareness of today's widespread availability of plug-in vehicles and highlight the benefits of all-electric and plug-in hybrid-electric cars, trucks, motorcycles, and more. Throughout the weekend of Sept. 28-29, 2013, events across the United States will celebrate the thrid annual National Plug In Day. (Xinhua/Fang Zhe) |