① As has been demonstrated repeatedly, a transportation infrastructure based around individuals in automobiles contributes to global warming, pollution, health problems and energy insecurity. Conversely, the idea behind a green transportation infrastructure is one that provides opportunities for people to get around their communities using their own power-such as walking or biking-or by other more environmentally sensitive means, like trains or buses. Sometimes, the best definition of a concept can be found by describing what it is not. All one has to do to get across the idea is to highlight the experience virtually all of us have shared at some point in our life (and for millions of Americans it can be literally an everyday experience): sitting in our motionless cars on a jam-packed highway as the vehicles spew emissions and pollution into the air. Even in cases when it's difficult or impossible to remove the car from the picture entirely, there are ways to green our transportation infrastructure and improve our health and quality of life. Therefore, we have to find out some ways to improve what's already in place. ② A lot of city dwellers hold that they prefer to drive cars to work. Sure, there are plenty of reasons keeping them in the cars. Convenience is obviously one, but having to wait at a bus stop and then sit or stand on a crowded bus while cars go by is definitely another big trouble. But cities around the world are doing their best to employ the environmental benefits of bus ridership by making them more attractive to ride. One major way is by creating lanes dedicated to buses so that they can zoom past cars and trucks on roadways. ③ Fun is just one of the many benefits to cities and towns that commit to making biking easy and safe. "Cleaner, healthier, quieter and safer neighborhoods," are the results of making bikeways and lanes a. priority, says Zehner,who argues that even though American cities are more spread out than those in Europe, they are still great candidates for bikes. If Americans can embrace the concept it will make us more like the rest of the world; indeed, Zehner says the bike is the predominant mode of transport globally, with around 2 billion people using them. ④ When it was originally built in 1889 ,the Poughkeepsie-Highland Railroad Bridge in Poughkeepsie,N.Y., was all about commerce and transportation, allowing people and goods to flow easily over the Hudson River. For years, the bridge sat unused after a fire nearly destroyed it in 1974 until a group called Walkway over the Hudson began its efforts to transform the bridge into a place for the public to enjoy. The group was finally successful in its efforts when the Walkway over the Hudson State Park opened in 2009-making it the longest pedestrian bridge in the world, which has since attracted more than 1 million visitors. Pedestrian bridges provide opportunities for alternative, environmentally friendly transportation modes such as hiking and walking. ⑤ Giving people the opportunity and encouragement to get out and walk sometimes takes a little creativity, especially in hyper-urban are- as like New York City. In the city's old Meatpacking District, a group of committed citizens have transformed what was once a piece of what would now be called green irfrastructure—an elevated railway line- and transformed it into a nearly 5-mile walkway and park on the west side of Manhattan called the High Line. What was a transportation route for meat and other agricultural goods heading into factories and warehouses from 1934 to 1980 is now a popular park with areas for public art and urban gardens. 16．Paragraph①_______.  17．Paragraph②_______.  18．Paragraph③_______.  19． Paragraph④_______.  20．Paragraph⑤_______. A．A little creativity is required to encourage people to walk.  B．People can use more electric vehicles instead of cars.  C．The green transportation encourages people to use human power or other environmentally friendly means.  D．Biking will do great good to the environment.  E．Bus lanes should be made to attract more bus riders.  F．Pedestrian bridges function as alternatives to biking and walking. 21．A transportation infrastructure will lead to______.  22．With the green transportation, people to get around their communities using their own power or______.  23．Difficult or impossible as it is to remove the car entirely, we have to find ways to improve ______. 24．The results of making bikeways and lanes a priority are ______. 25．Sometimes ______ can give people the opportunity and encouragement to get out and walk.  A．What’s already in place  B．global warming, pollution, health problems and energy insecurity  C．a little creativity  D．cleaner, healthier, quieter and safer neighborhoods  E．by other more environmentally sensitive means  F．the government's great support