题目内容：
回答题：Powering a City? It’s a Breeze.
The graceful wooden windmills that have broken up the flat Dutch landscape for centuries — a national symbol like wooden shoes and tulips — yielded long ago to ungainly metal-pole turbines.
Now, windmills are breaking into a new frontier．Though still in its teething stages, the “urban turbine” is a high-tech windmill designed to generate energy from the rooftops of busy cities．Lighter, quieter, and often more efficient than rural counterparts, they take advantage of the extreme turbulence and rapid shifts in direction that characterize urban wind patterns.
Prototypes have been successfully tested in several Dutch cities, and the city government in the Hague has recently agreed to begin a large-scale deployment in 2003．Current models cost US $8, 000 to US $12, 000 and can generate between 3, 000 and 7, 000 kilowatt hours of electricity per year．A typical Dutch household uses 3,500 kilowatt hours per year, while in the United States, this figure jumps to around 10, 000 kilowatt hours.
But so far, they are being designed more for public or commercial buildings than for private homes．The smallest of the current models weigh roughly 200 kilograms and can be installed on a roof in a few hours without using a crane.
Germany, Finland and Denmark have also been experimenting with the technology, but the ever-practical Dutch are natural pioneers in urban wind power mainly because of the lack of space．The Netherlands, with 16 million people crowded into a country twice the size of Slovenia, is the most densely populated in Europe.
Problems remain, however, for example, public safety concerns, and so strict standards should be applied to any potential manufacturer．Vibrations are the main problem in skyscraper-high turbine．People don’t know what it would be like to work there, in an office next to one of the big turbines．It might be too hectic.
Meanwhile, projects are under way to use minimills to generate power for lifeboats, streetlights, and portable generators．“I think the thing about wind power is that you can use it in a whole range of situations,” said Corin Millais, of the European Wind Energy Association．“It’s a very local technology, and you can use it right in your backyard, I don’t think anybody wants a nuclear power plant in their backyard.”
What are the symbols of the Netherlands according to the first paragraph? A．The flat landscape.
B．Wooden shoes and wooden windmills.
C．Metal-pole turbines.
D．Both A and C
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