Question

    Since 1970, North America has lost more than 2.9 billion birds, according to a study recently published in the journal Science. In less than half a century, the bird population has declined by some 29 percent, or more than 1 in 4 birds. For the first time, researchers have discovered that rare species aren't the only birds suffering population loss. In fact, common birds-including beloved backyard friends like sparrows and blackbirds-are taking the biggest hit.

The new study used nearly 50 years of data collected largely by bird watchers and citizen scientists. "A total of 419 native migratory species experienced a net loss of 2.5 billion individuals," the study says. More than 90 percent of the total loss can be found among just 12 bird families. Some of these widespread birds can thrive almost anywhere. The large-scale loss of these hardy birds reveals they're struggling to survive throughout the world/

Birds are considered indicator species because they're crucial to ecosystems, and their populations anticipate the environment's health. Birds are "amazingly efficient" at spreading seeds. Birds also keep insect populations in check. Even the smallest bird helps control the spread of plants or insects.

The new study, however, identifies the losses without knowing all the causes. Scientists do identify habitat loss as the biggest challenge. Climate change, disrupted migration patterns and pesticide use are also major factors. Industrial agriculture may present a bigger challenge. The species disappearing most rapidly—sparrows, blackbirds and larks—are associated with agriculture. In recent decades, agriculture has grown to produce more food, but cleared landscapes have become unlivable for birds.

“We need to change the way we grow food. Birds are signaling that we are doing it wrong, "as the study says. The study offers the example of the 1990s effort to switch to no-till farming, which reduced greenhouse gases and soil erosion（侵蚀）. “Farmers are innovators. And they've done it before. This is a great opportunity to have a huge impact on birds."

1.What's the study mainly about？

A.The climate issues. B.The disappearing birds.

C.The agricultural problems. D.The environmental protection.

2.How is the second paragraph mainly developed？

A.By listing figures. B.By giving examples

C.By analyzing reasons. D.By making comparisons.

3.What's the main reason behind the birds' habitat loss？

A.Climate change. B.Greenhouse gases.

C.Industrial agriculture. D.Disrupted migration patterns.

4.What does the study suggest as a solution？

A.Producing more food. B.Clearing more landscapes.

C.Reducing the use of pesticide. D.Adopting new means of farming.

Answer

1.B

2.A

3.C

4.D

【解析】

这是一篇说明文。文章主要介绍了一项新的研究的发现，即普通鸟类的数量锐减及其背后的原因以及解决方案。

1.细节理解题。根据文章第一段中“For the first time, researchers have discovered that rare species aren't the only birds suffering population loss. In fact, common birds-including beloved backyard friends like sparrows and blackbirds-are taking the biggest hit.”可知，研究人员首次发现，珍稀物种并不是唯一遭受种群损失的鸟类。事实上，普通的鸟类——包括像麻雀和黑鸟这样在后院的好朋友——受到的伤害最大。由此可知，这个研究主要是关于正在消失的鸟类的。结合选项，故选B。

2.细节理解题。根据文章第二段中“The new study used nearly 50 years of data collected largely by bird watchers and citizen scientists. "A total of 419 native migratory species experienced a net loss of 2.5 billion individuals," the study says. More than 90 percent of the total loss can be found among just 12 bird families.”可知，作者列举了大量数据来介绍该项新研究，故选A。

3.细书理解题。根据文章第四段中“The new study, however, identifies the losses without knowing all the causes. Scientists do identify habitat loss as the biggest challenge.”可知鸟类数量锐减最重要的原因就是鸟类栖息地的减少；以及第四段的最后一句“agrieulure has grown to produce more food，but cleared landscapes have become unlivable for birds.”可知，为了生产更多的粮食，人们开垦了很多土地。但是这些新开垦的土地却不再适合鸟类居住。故鸟类栖息地丧失的主要原因是农业产业。故选C。

4.推理判断题。根据文章最后一段中““We need to change the way we grow food. The study offers the example of the 1990s effort to switch to no-till farming, which reduced greenhouse gases and soil erosion（侵蚀）.”可知，我们需要改变种植食物的方式。 “免耕农业”可以减少温室气体和土壤的侵蚀，从而减少对鸟类的伤害。由此推断出，这项研究提出的解决方案是采用新的耕作方法。故选D。