中档题型高分练（07）阅读理解（C、D篇）+完形填空

中档题型高分练（二） 阅读理解（C、D篇）+完形填空 I.阅读理解 C A new study finds too much light at night can cut the number of seeds a plant produces. Researchers put up street lights in Swiss meadows, far from any real street. The setup mimicked(模拟) urban light pollution. In these now-light-polluted fields, flowers had 62 percent fewer night visitors — insect pollinators (传粉者)— than the flowers in dark meadows did. Cabbage thistles are the most common flowers in these meadows. Fewer insect visitors at night could mean less pollen (花粉) pollinated from plant to plant (the first step in producing seeds). “For the thistles, daytime pollinator visits didn’t make up for this loss at night,” says Eva Knop, an ecologist at the University of Bern in Switzerland. Overall, night-lit plants produced one-eighth fewer seeds than plants that got full nights of darkness did. “Light pollution might affect a whole network of plants and their pollinators,” Knop and her colleagues now suggest. Indeed, night pollination is not just a lonely business for a few special plants. There are lots of links between production of pollen by night and that by day. Plants with a lot of night visits are often very busy by day, too. Light at night that decreases seed numbers could over time mean fewer new plants. And fewer plants could mean less food and shelter for daytime insects. Therefore, a lot of pollinators working day and night shifts could be affected, which is what Knop worries about. The new study is the first to show how artificial light affects plants’ ability to produce seeds. The test is also unusual because it considers all kinds of insect pollinators instead of focusing only on night-flying insects. The researchers paid special attention to the cabbage thistle, but they also mapped which kinds of insects visited other plants by day or night. 1．Why were street lights put up in the meadows? A．To copy light pollution. B．To promote urbanization. C．To accelerate plant growth. D．To attract insect pollinators. 2．Wh