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生态脊柱__________ spine

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废弃的地下货运车站a d__________ underground trolley station

交通堵塞traffic c__________

可持续工业园__________ industrial parks

Skyscrapers (High buildings) are the symbol of urban life. City people are used to seeing tall office buildings, multistory five star hotels, and apartment towers with thousands of residents. Farms, on the other hand, are associated with rural life. However there are experts who think that some skyscrapers should become farms in order to meet the increasing food needs of our planet.By 2050, some social scientists suggest, almost 80 percent of the earth’s population could live in cities. In addition, the human population could increase to 9. 1 billion people during that time yet the amount of land available for farming will be the same. If current farming practices don’t change by the middle of this century, one prominent expert claims, we will need an area of new land larger than Brazil to produce enough food for the planet.Vertical farms, where urban farmers could grow crops like wheat in environmentally friendly skyscrapers, could be the solution. In spite of concerns over high costs, environmental health experts want to make these urban farms a reality and use these skyscrapers to grow crops. They believe that we can increase food production by changing our thinking from out to up.Supporters say that vertically grown food would be cultivated with minimal effects on the environment. Unlike traditional farming, vertical farming would not force animals out of their habitats by taking over large areas of land, nor would it pollute the air with the use of heavy farming equipment. Moreover, vertical indoor farming could produce crops constantly and crops would not suffer from weather-related problems like drought or flooding. Also, the use of chemical pesticides for controlling insects would be minimal.Critics of vertical farming point out that although crops growing in a tall glass building would get natural sunlight during the day, it wouldn’t be enough. The plants closest to the windows would grow much more quickly than the plants further inside. The plants growing away from the windows may not produce as many or as high quality vegetables. For these reasons, vertical farms would need additional light sources.Researchers have found that even in single-story greenhouses, artificial light is often needed for rear-round crops. For example, Thanet Earth is a large indoor farming complex in the United Kingdom that produces 15 percent of the British lettuce crop. During the winter, the complex uses artificial light for 15 hours a day. Experts have concluded that generating enough solar energy to support growth requires an area about 20 times larger than the planting area. Therefore, natural light cannot be a practical solution for vertical farms.Vertical farming is expensive, and unless people want to pay more for fresh, local food, the technique may not succeed in the marketplace. Experts agree that creative farming practices are needed to support the planet’s need for more and more food at affordable costs, both to the farmer and to the consumer. Vertical farms may be a small-scale answer, but the best ideas could be yet to come.