阅读专项之社会历史类阅读

阅读专项之社会历史类阅读 （一） Man’s best friend could be one of the environment’s worst enemies, according to a new study that says that your pet dog’s carbon pawprint（碳足迹） is more than double that of a sports car.  Yet this point of view, made by New Zealanders Robert and Brenda Vale, has angered pet owners who feel they are being picked out as troublemakers.   The Vales, researchers in sustainable（可持续的） living, looked at popular brands of pet food and calculated that a medium-sized dog eats about 164 kilos of meat and 95 kilos of grain a year.    Combining that with the energy needed to produce that food, it means a medium-sized dog has an annual footprint of 0.84 hectares（公顷）, about twice the 0.41 hectares required by a sports car driving 10,000 kilometers a year, including energy to build the car.  “Owning a dog really is quite an extravagance（奢侈）, mainly because of the carbon footprint of mean. Other animals aren’t better for the environment,” the Vales say.    Cats have an eco-footprint of ab