Birds are a critical part of our ecological system. But more than ever, birds are threatened by human pollution and climate chan

admin2017-02-25 36

问题 Birds are a critical part of our ecological system. But more than ever, birds are threatened by human pollution and climate change.
We need the birds to eat insects, move seeds and pollen around, transfer nutrients from sea to land, clean up after the mass death of the annual Pacific salmon runs, or when a wild animal falls anywhere in a field or forest.
How could we enjoy spring without the birds flitting busily in our garden or dropping by to check out the flowers in our urban window box? Can you contemplate America without the soaring bald eagle, or even those scavengers like the pigeons and gulls that clean up discarded food scraps on our city streets and waterfronts? How diminished our lives would be without them?
Scavenging eagles and condors need hunters to behave responsibly and bury, or remove, the remains of any shot deer peppered with fragments of lead bullets. Loons, ducks and other water birds will be poisoned by lead bullets and lead fishing sinkers if we allow such objects to drop in their feeding space.
All sea and shore birds, even the puffins and guillemots of the otherwise pristine Aleutians, need us to make sure that no other heavy metals, like mercury and cadmium, are dumped in rivers and make their way across the oceans.
Birds like the terns, knots and shearwaters that migrate between the far north and deep, deep, south of our planet need people everywhere to cease and desist from filling in their wetland fuel stops and rest stations, and from constructing golfing resorts and factories in their feeding and breeding grounds.
Seabirds are among the most endangered vertebrate species on the planet, with the International Union for Conservation of Nature classifying 97 species as globally threatened, and 17 in the highest category of critically threatened. Of greatest concern are the pelicans of the southern oceans and the spectacular, but slow-breeding albatross.
Plastic bags must be eliminated from natural environments so sea and shore birds don’t mistakenly carry such debris back to feed their chicks, with invariably lethal consequences. The albatross, cormorants and herons need us to stop over-fishing and compromising their normal food supply.
The pelicans, penguins and all the birds that inhabit, or visit, our coastlines need us to ensure that we do not dump oil into gulfs and bays, or release so much carbon dioxide into the atmosphere that the oceans turn acidic and we lose the mussels and oysters, the mass of calcareous plankton that feeds so many creatures, and the coral reefs that nurture enormous numbers of edible species.
Think about it: We share this small green planet. As they fly, feed and nest, the birds monitor the health of the natural world for us. provided that we, in turn, make the effort to access that key information.
The birds and humans are both large, complex and ultimately vulnerable organisms that inhabit the top of the food chain. At the end of the day, their fate will be our fate.
What does the underlined word "them" in PARAGRAPH THREE refer to?

选项 A、Birds.
B、Flowers.
C、Food scrapes.
D、Scavengers.

答案A

解析指代题。根据第三段的内容，让读者想象没有鸟类的生活，可以推测“How diminished ourlives would be without them?”中的them指的就是“鸟类”。故选A。

转载请注明原文地址:https://kaotiyun.com/show/RE3v777K

本试题收录于：英语学科知识与教学能力题库教师资格分类

英语学科知识与教学能力

教师资格

相关试题推荐

随机试题

最新回复(0)

Birds are a critical part of our ecological system. But more than ever, birds are threatened by human pollution and climate chan

英语学科知识与教学能力

教师资格