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  3. Traffic fumes render the scent of flowers barely recognizable to honeybees and could have a serious impact on their ability to f

Traffic fumes render the scent of flowers barely recognizable to honeybees and could have a serious impact on their ability to f

admin2017-11-08  51
问题    Traffic fumes render the scent of flowers barely recognizable to honeybees and could have a serious impact on their ability to find food, new research has found. Scientists discovered that reactive pollutants in diesel (柴油) destroyed key chemicals in the odour of oilseed flowers making them smell different to the bees.
   "Honeybees have a sensitive sense of smell and an exceptional ability to learn and memorize new odours," said Tracey Newman, a neuroscientist at the University of Southampton. "The effect of diesel fumes on flower scent could have serious detrimental effects on the number of honeybee colonies and pollination (授粉) activity." Three-quarters of the world’s food crops rely on bees and other natural pollinators " Pollinator services are crucial to humankind," said Newman.
   But there have been serious declines in natural pollinators in recent decades. A combination of factors is blamed, including the huge loss of the flower-rich habitats that sustain bees, as well as disease, and the impact of agricultural insecticides. The revelation that traffic fumes could be adding to the problems is significant, said Guy Poppy, a professor and ecologist at Southampton, who also worked on the research. He said, "Diesel exhaust is not the root of the problem, but clearly, with all the other stressors, adding another one is likely to be detrimental to bee health."
The study, published in the journal Scientific Reports, tested bees’ ability in the laboratory to recognize the aroma of oilseed rape flowers. Bees were strapped down and taught to associate floral scents with food in the form of sugar solutions. Once the bees learned the connection they began sticking their tongues out in anticipation of food even if it was not offered—an indication that they recognized the smell. When the scent was presented without pollutants the bees recognized it 98% —99% of the time. But after the scent was mixed with levels of diesel exhaust matching those found at roadsides, the bees only recognized it 30% of the time.
Which of the following is not the reason for the decline of natural pollinators?
选项 A、A large amount of the flower production places disappear.
B、Heavy use of agricultural insecticides.
C、Traffic fumes pollute the atmosphere.
D、Decline on the number of honeybee colonies.
答案D
解析 根据题干可以将该题定位至第三段。第三段指出了自然授粉活动次数严重下滑的原因：多花蜜蜂栖息地数量的减少；疾病和农业杀虫剂的影响；交通废气，所以很容易排除A、B和C选项。
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