We are all aware of the damaging pollution that’s created by driving petrol and diesel(柴油) vehicles. Many of the world’s cities are blocked with traffic, creating fumes containing gases such as nitrogen oxides.The solution for a cleaner, greener future could be electric vehicles. But how optimistic should we be? There was much excitement last year when the UK government announced it will ban the sale of new petrol and diesel cars from 2030. But is that easier said than done?

The road to global traffic being totally electric is still a long way off. Currently, battery life is an issue ——a fully charged battery won’t take you as far as a full tank of petrol. There are also limited numbers of charging points to plug an electric vehicle into. Of course, technology is always improving. Some of the biggest tech companies, like Google and Tesla, are spending huge amounts of money developing electric cars. And most of the big car manufacturers are now making them too. Colin Herron, a consultant on low-carbon vehicle technology, told the BBC, “The big leap forward will come with solid-state batteries, which will appear first in mobile phones and laptops before they progress to cars. “These will charge more quickly and give cars a bigger range. Cost is another issue that may discourage people switching to electric power. But some countries offer incentive, such as cutting prices by reducing import taxes, and not charging for road tax and parking. Some also provide exclusive lanes for electric cars to be driven on, overtaking traditional cars which might be stuck in jams.

These kinds of measures have made Norway the country with the most electric cars per capita(人均) at more than thirty electric cars per 1000 inhabitants. But Colin Herron warns that “electric motoring” doesn’t mean a zero-carbon future. “It’s emission-free motoring, but the car has to be built, the battery has to be built, and the electricity does come from somewhere.” Maybe it’s time to think about making fewer journeys or using public transport.

Before the Second World War, everyone everywhere rode their bicycles—and then with the dawn of the 1950s the automobile killed the cycling culture. In the 1960s Copenhagen was very polluted and crowded with cars. It took the city planners and politicians a long time to reclaim (恢复) the streets of Copenhagen. 【小题1】

Rush hour in Copenhagen is when 45% of the population travel by bicycle to their places of work or study each day. 【小题2】 It looks very different there than in my home country of Canada—where there is a very low percentage of the population who ride bicycles.

The environmental concern is a minor part of what encourages people to cycle in Copenhagen. 【小题3】 Is there a linkage to cycling and why Copenhagen is often ranked the happiest city on the planet?

The Danish don’t have big monuments, they have Hans Christian Andersen’s “Little Mermaid (美人鱼),” which is life-size. This captures the spirit of the city; laid back, practical and responsible. Their monuments are big wind turbines (发电机).

【小题4】 There are many other renewable energies. We just need to look around mother nature’s playground.

Trees bring rain. When they sway in the wind, they purify the air. 【小题5】 When the leaves drop to the ground, they help the soil become fertile but hold their shape for a long time—no matter how hard it rains. When you cut down trees for building, for farming, the land and rivers dry up. The springs as God made them are gone, as is every living thing found that requires water to survive.

Before you go on your next two-wheeled adventure, make sure you’re familiar with the ins and outs of bicycle safety. This holds true whether you’re riding a traditional bike or an e-bike — one powered by an electric motor in addition to your pedaling.

Many of the safety recommendations are the same for both types of bikes. Wear a helmet. 【小题1】 Make sure you’re visible to motorists (some e-bikes now come with lights). Know how to use your arm to signal turns (left: extend your left arm out to the side; right: extend your right arm or bend your left arm up at a right angle). Don’t talk on the phone, text, or listen to music. 【小题2】

Be sure your e-bike is ready to ride. That starts with checking that the tires are inflated and the brakes are working properly. If the bicycle hasn’t been used for a while, take it for a tune-up before you take it for a ride. 【小题3】 And before and after every ride, inspect your bicycle for damage.

【小题4】 This is also important for e-bike riders. “With the ability to go faster comes the responsibility to know when you should slow down,” says Ash Lovell, electric bicycle policy director at People for Bikes, a cyclist advocacy organization.

Know the rules of the road. “When you’re riding in the street, even in a protected bike lane, read the signals, pay attention to the lane markings, and check the signage to see where e-bikes are allowed,” Lovell says. 【小题5】 Signs in those states may specify which types of bikes are allowed on which roads and paths. Check the People for Bikes website (peopleforbikes.org) for more information.