Electric vehicles are mostly by gas-powered cars. But more electric car     1     (model) will come out in the next few years. Governments,    2     (particular) in European countries and China, are pushing this change     3    (reduce) carbon emissions and fight global warming.

Keeping electric motors charged is cheaper than    4     (buy) gas. But how long does it take to charge an electric vehicle? There are several ways to charge electric vehicles and times range from minutes    5    half a day. The slowest way to charge is on a standard 120-volt (伏特) charger,    6    adds just a few miles of range per hour. For trips that involve hundreds of miles in a single day, drivers typically rely on DC fast chargers. These chargers are much more expensive to install and thus    7    (rare). For would-be buyers, the lengthy charge times can sound alarming. And convincing them to try their first electric vehicle    8    (be) a challenge for the auto industry.

Going electric is not only an eco-friendly goal    9    also a business reality, according to industry analysts. But even if the general path ahead is widely agreed on,    10    speed of the change is far from clear.

Like all big cities, Paris has a traffic problem: lots of cars, traffic jams and pollution from exhaust fumes (废气). So since 2007, the city     1     (begin) a plan to improve the situation.

Under the Velib scheme (公共自行车计划), people can take a bicycle, use it as long as they want, and then leave it at the same or another bicycle station. The first half hour is free,     2     if you don’t return it after 30 minutes, you have to pay. The bicycles are     3     heavy as 25 kilograms, and they’re all grey and have baskets.

Paris isn’t the first city     4     (operate) a scheme like this. Not everybody thinks it’s a great idea. One Parisian (巴黎人) said, “These bicycles are only suitable     5     short journeys.”

A city spokesman said, “The bicycle scheme won’t solve all our traffic problems, but it might work in     6     (reduce) air pollution. Traffic, together with factory fumes,     7    (be) a big problem. Global warming and dramatic climate changes are becoming more and more serious,     8     is partly because rain-forests are     9     (gradual) disappearing. And it’s also because there’s so much pollution. Unless we do something now, there will be more traffic jams and temperatures will continue to rise, so the problems in our environment will get even     10     (bad).”