题型:阅读理解 题类:常考题 难易度:普通
宁夏育才中学2018届高三上学期英语期末考试试卷
Bees and other pollinators(传粉者) use smells to track down fresh flowers. Air pollutants can weaken those scents(气味). Scientists had worried this might make it harder for some pollinators to find a meal.
Many animals help pollinate plants. Species that do this include bees, butterflies, etc. But for many reasons, the pollinators available to help plants in this way are decreasing. Scientists think a loss of habitat(栖息地)can be one factor. Diseases and exposure to poisonous chemicals also count.
Jose Fuentes points to air pollution as another possible factor. He's an atmospheric scientist at Pennsylvania State University. In an earlier study, he showed some air pollutants could weaken or destroy scents emitted(发出)by flowers.
Searching for a meal leaves pollinators out in the open and at risk of becoming other animal's lunch. And any time spent hunting food is time away from their duties back home, like protecting a hive(蜂巢)or nest, explains T'ai Roulston. He's an insect biologist at Virginia University. Roulston worked with Fuentes on the new study.
In the study, the researchers focused on five kinds of representative scent molecules(分子)plants emit. One molecule they looked at, for example, is called beta-myrcene. Many flowers give off this chemical into the air. Normally, this gas can travel some 800 meters from its flower source. But in polluted air, this same molecule could travel only half as far.
Worse still, air pollution might do more than just weaken scent plumes(气味烟云).Chemical reactions between air pollutants and plumes may transform the flowers' smells, creating new scents. And these scents may be unrecognizable to pollinators.
That's certainly Fuentes' concern. So, he says his next research project will look at how insects handle any new flower scent. "It's possible that some insects will change ways to detect and use these new molecules to find food," he says.
The following are introductions to some programs that BBC I will show on TV.
12:25a.m Tuesday | The Real Swiss Robinson Family Laura worried that her children have had their life too easy due to her husband's career in big business, so she decides to take her teenagers to the Cook Islands to experience the simple life. They face storms and a lack of food, but Laura is happy as their local guide shows them the island's wealth of rare fruits and foods. |
11:00a.m Wednesday | A team have come across an armed man who is holding two baby chimps who were trapped. One of them, David, is sent to a medical emergency in the forest. Later a center director, Nielsen, finds a suitable place to set free more rescued animals. |
7:50p.m Thursday | Lost Building of Britain Simon Thurley visits the ruins of Glastonbury Abbey(修道院), which ,before its destruction by Henry VIII, was famous for some of the most amazing stained glasses of its age. It also had a great deal of financial power, acting as the center of an influential business empire. |
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