Today some people call Amsterdam the “City of Bicycles” because it is a city which is flat and convenient for bicycles.

In the 1960s, a group of cycling fans had an idea. They believed that it would be better for everybody if only bicycles were allowed in the city center. They were __ that this would help to save energy, reduce pollution and provide free public transport. The group painted hundreds of bicycles __ and placed them in public places around Amsterdam for people to use. __ was allowed to take them and use them for short journeys, whether he was a local or a foreigner. Wherever someone finished a journey, they would send the bicycles back. Unfortunately, it was not long before all the bicycles were stolen by thieves.

__ , more than thirty years later, the a white bike is back in town-this time with a computer (芯片）to __ its every move! To take a bicycle, you have to put a special card inside. The new “white bike” is not white any more but is an __ design with bright colors. The bikes are parked at special parking places and people who want to use them have to take them to another place that has enough room.

There is already less traffic in central Amsterdam __ both locals and tourists have been using the white bikes. Thanks to the good ideas of lots of people, like the cycling fans in the 1960s t many people around the world have been enjoying city center streets without cars for many years.