There’s a battle storming in the streets of America. Anyone who regularly rides a bicycle knows all about this. Some motorists shout at two-wheeled travelers, who slow traffic. A few will do even worse.

The New York Times reports that incidents of aggression toward bicycle riders appear to be growing. Even though actually every state allows bicyclists the same right as motorists to use the streets, many drivers still refuse to accept this. They view themselves as Kings of the Road --- an impression that has been strongly built by the transportation planning profession, which has designed our cities as if people didn’t exist outside of their cars.

But a big new idea to settle this conflict and improve life in the streets for everyone is now taking root among community activists, urban planners and traffic engineers.

“Too many of our streets are designed only for speeding cars. They’re unsafe for people on foot or bike. Now, in communities across the country, a movement is growing to complete the streets. States, cities and towns are asking their planners, engineers and designers to build road networks that welcome all citizens,” declares the website of a new organization promoting this idea, “Complete the Streets” , the best idea to hit our communities since pizza, or even the bicycle itself.

My home of Minneapolis is one of the biking capitals of America. But it hasn’t always been that way. When I moved here many years ago, I was shocked at the strong hostility directed toward me whenever I dared ride my bike down the street. Drivers would suddenly turn in my direction, and then laugh as they nearly knocked me onto the ground.

As the amount of bikes on Minneapolis streets has grown, people have become much more comfortable sharing the road with two-wheelers. Indeed, I get the impression that most motorists now envy rather than hate me, and can’t wait to get home where they can jump on their own bikes. This will happen everywhere as more and more Americans discover biking as a great way to get around, save money, lose weight, protect the planet and have fun.

You might be surprised to know that bicycles have existed for about two hundred years, but no one is sure who first made this popular two-wheeled machine.

【小题1】The front wheel was much bigger than the back one, and also there weren't any pedals (踏板), Riders had to move themselves forward by pushing their feet against the ground.

【小题2】 In 1879 an Englishman had the idea of connecting them to the back wheel with a chain. Gears(齿轮), which made things much easier for those cycling uphill, first appeared in the 1890s.

There are now about one billion bicycles in the world.【小题3】They have to compete with cars on the streets of all the world' s cities, and the two forms of transport don' t always mix well. In London in 2005, for example, over 300 cyclists were either killed or seriously hurt in accidents.

Because bicycles are much more environmentally friendly than cars, now many governments encourage people to ride rather than drive.【小题4】The number of yearly journeys made by bicycle in London has increased 50% over the last five years.

However, although one in three British people owns a bicycle, they still don't use them nearly as much as they could 【小题5】.

It is hoped that more people will rely on bicycles to move around. The reasons are obvious--cycling helps to protect the environment, keep us fit, and it is often not only cheaper but also quicker than travelling by car in many cases.

Riding the bus to school could be keeping some kids out of class. Most school buses run on fuel. Those buses send out pollution, including tiny particles and gases. Bus riders get exposed to high levels of this pollution. When breathed in, it can lead to breathing problems, such as asthma (哮喘), which may keep kids home from school. But replacing the worst-polluting buses should cut down on student absences, a new study shows.

The study focused on schools that were asked to take part in a U. S. government program. The program offered schools cash back for money spent on cleaner school buses. The 2, 816 school districts in the new study all asked for the money. But not all got it. Only 383 were picked to receive funding. Winning districts could buy new buses and desert old ones.

The program started in 2012. From 2012 to 2017, the winning districts very likely had less bus pollution. And a year after getting new buses, student attendance had improved in those districts. For an average district of 10, 000 students, about six more students attended school each day in the winning districts. Districts that replaced the oldest buses had an average of 45 more students in school each day.

Those numbers may sound small, but they can add up, says Meredith Pedde, an environmental epidemiologist (流行病学家). Almost 3 million U. S. kids ride school buses more than 20 years old, her team figures. Replacing all of those old buses could mean 1.3 million fewer student absences each year, the data suggest. And school attendance matters for student achievement.

Now the U. S. Environmental Protection Agency (EPA) has a new program for school buses.   It’s offering $5 billion through 2026 to replace old fuel buses with cleaner ones. Almost all U. S. school districts can apply for the new rebates. But schools in low-income areas and in rural areas will get priority. Kids in these areas tend to face the most health risks from old buses, EPA notes. And anything that cuts air pollution, Pedde says, should improve student health.