Even before canaries (特高频噪声) were brought into coal mines to alert workers to the presence of poisonous gas, birds were giving us early warning calls signaling the Earth’s deteriorating environmental health. Global bird populations have shrunk by up to 25% since preagricultural (农业社会前的) times. Over the past 300 years, farmland has expanded from six percent of the Earth’s surface to nearly 33%.
Today, three quarters of threatened bird species depend on forests as their principal habitat; each year, however, some 13,000,000 hectares of forests are destroyed, an area the size of Greece. Nearly half the woodlands lost are relatively undisturbed primary forests that are home to a number of sensitive birds and other creatures.
Direct exploitation, including hunting for food and capture for the pet trade, is the second greatest danger after habitat loss, while next is the intentional or accidental introduction of non-native species. As people travel to all parts of the globe, so too do the pests and pets that prey on, out-compete, or alter the habitat of native wildlife.
Pollution poses an additional risk, affecting 12% of the threatened bird species. In addition to direct poisoning from fertilizer and pesticide applications, runoff of chemicals contaminates the wetlands that migrating waterfowl rely on. Persistent organic pollutants accumulate in the food chain and can lead to deformities, reproductive failure, and disease in birds.
Worldwide, one-third of plant and animal species could become extinct by 2050 as a result of climate change, a relatively new threat. Global temperature spikes have brought severe alterations to the migration, breeding, and habitat ranges of some birds.
In addition to these looming dangers, seven percent of threatened bird species are at risk from incidental mortality. A rapid decline in seabird populations over the last 15 years corresponds with the growth in commercial longline fisheries. In Europe, Central Asia, and Africa, electrocution on power lines has caused the mass mortality of raptors. Moreover, countless birds die each year from collisions with windows, the number-one cause of U.S. avian mortality.
If birds disappear, so do the economically valuable services they provide. Preventing the extinction of additional bird populations depends largely on protecting the world’s remaining wild spaces and preserving the health of our natural and altered ecosystems.
Reports that the ivory-billed woodpecker, long thought to be extinct, is still with us thrilled bird watchers and others, but this sort of second chance seldom occurs in nature. Even with continued habitat protection, once wildlife populations drop dramatically, a rebound is far from guaranteed. Without stabilizing climate and human numbers, putting fences around all the parks in the world will not lie enough to protect threatened species.
According to the author, which is the most feasible way to protect birds

A:Use fences to protect all the parks in the world. B:Try to protect wild space and nature. C:Abandon the economic values that birds can bring. D:Rely less on agriculture and return farmlands to forests.

Even before canaries (特高频噪声) were brought into coal mines to alert workers to the presence of poisonous gas, birds were giving us early warning calls signaling the Earth’s deteriorating environmental health. Global bird populations have shrunk by up to 25% since preagricultural (农业社会前的) times. Over the past 300 years, farmland has expanded from six percent of the Earth’s surface to nearly 33%.
Today, three quarters of threatened bird species depend on forests as their principal habitat; each year, however, some 13,000,000 hectares of forests are destroyed, an area the size of Greece. Nearly half the woodlands lost are relatively undisturbed primary forests that are home to a number of sensitive birds and other creatures.
Direct exploitation, including hunting for food and capture for the pet trade, is the second greatest danger after habitat loss, while next is the intentional or accidental introduction of non-native species. As people travel to all parts of the globe, so too do the pests and pets that prey on, out-compete, or alter the habitat of native wildlife.
Pollution poses an additional risk, affecting 12% of the threatened bird species. In addition to direct poisoning from fertilizer and pesticide applications, runoff of chemicals contaminates the wetlands that migrating waterfowl rely on. Persistent organic pollutants accumulate in the food chain and can lead to deformities, reproductive failure, and disease in birds.
Worldwide, one-third of plant and animal species could become extinct by 2050 as a result of climate change, a relatively new threat. Global temperature spikes have brought severe alterations to the migration, breeding, and habitat ranges of some birds.
In addition to these looming dangers, seven percent of threatened bird species are at risk from incidental mortality. A rapid decline in seabird populations over the last 15 years corresponds with the growth in commercial longline fisheries. In Europe, Central Asia, and Africa, electrocution on power lines has caused the mass mortality of raptors. Moreover, countless birds die each year from collisions with windows, the number-one cause of U.S. avian mortality.
If birds disappear, so do the economically valuable services they provide. Preventing the extinction of additional bird populations depends largely on protecting the world’s remaining wild spaces and preserving the health of our natural and altered ecosystems.
Reports that the ivory-billed woodpecker, long thought to be extinct, is still with us thrilled bird watchers and others, but this sort of second chance seldom occurs in nature. Even with continued habitat protection, once wildlife populations drop dramatically, a rebound is far from guaranteed. Without stabilizing climate and human numbers, putting fences around all the parks in the world will not lie enough to protect threatened species.

According to the author, which is the most feasible way to protect birds（）

A:Use fences to protect all the parks in the world. B:Try to protect wild space and nature. C:Abandon the economic values that birds can bring. D:Rely less on agriculture and return farmlands to forests.

It is often difficult for visitors to understand Americans’ lack of desire for privacy. They are not a nation of walled gardens and closed gates. Their yards normally run into one another without fences；they often visit one another’s homes without being invited or telephoning first; they leave their office doors open while they work.
Their lack of desire for privacy probably results from their history as a nation. America is a big country. There have never been walled cities in the United States, nor was there the need for Americans to protect themselves from neighboring states. During the early years, America had so few settlers that neighbors were very important; they were not to be shut out by doors and fences. Neighbors offered protection and helped in the hard work of settling the land. They depended upon each other.
From the nation’s early history has come the desire for openness rather than privacy. Visitors will notice this desire in a number of small ways; there may be rooms in American homes that do not have doors or that have glass walls. If you notice that people forget to close your door when they leave your room, do not think that this is rude, help them to learn that you would like it to be closed, or else become accustomed to new ways. In either case, be patient with the differences.

Which of the following is true（　）

A:People walled their yards with fences. B:The settlers in early years needed their neighbors’ help very much. C:People get used to American openness. D:It is difficult to follow the American way of life.

It is often difficult for visitors to understand Americans’ lack of desire for privacy. They are not a nation of walled gardens and closed gates. Their yards normally run into one another without fences；they often visit one another’s homes without being invited or telephoning first; they leave their office doors open while they work.
Their lack of desire for privacy probably results from their history as a nation. America is a big country. There have never been walled cities in the United States, nor was there the need for Americans to protect themselves from neighboring states. During the early years, America had so few settlers that neighbors were very important; they were not to be shut out by doors and fences. Neighbors offered protection and helped in the hard work of settling the land. They depended upon each other.
From the nation’s early history has come the desire for openness rather than privacy. Visitors will notice this desire in a number of small ways; there may be rooms in American homes that do not have doors or that have glass walls. If you notice that people forget to close your door when they leave your room, do not think that this is rude, help them to learn that you would like it to be closed, or else become accustomed to new ways. In either case, be patient with the differences.
Which of the following is true

A:People walled their yards with fences. B:The settlers in early years needed their neighbors’ help very much. C:People get used to American openness. D:It is difficult to follow the American way of lif

It is often difficult for visitors to understand Americans’ lack of desire for privacy. They are not a nation of walled gardens and closed gates. Their yards normally run into one another without fences；they often visit one another’s homes without being invited or telephoning first; they leave their office doors open while they work.
Their lack of desire for privacy probably results from their history as a nation. America is a big country. There have never been walled cities in the United States, nor was there the need for Americans to protect themselves from neighboring states. During the early years, America had so few settlers that neighbors were very important; they were not to be shut out by doors and fences. Neighbors offered protection and helped in the hard work of settling the land. They depended upon each other.
From the nation’s early history has come the desire for openness rather than privacy. Visitors will notice this desire in a number of small ways; there may be rooms in American homes that do not have doors or that have glass walls. If you notice that people forget to close your door when they leave your room, do not think that this is rude, help them to learn that you would like it to be closed, or else become accustomed to new ways. In either case, be patient with the differences.

Which of the following is true（　）

A:People walled their yards with fences. B:The settlers in early years needed their neighbors’ help very much. C:People get used to American openness. D:It is difficult to follow the American way of life.

下面有3篇短文，每篇短文后有5道题，每道题后面有4个选项。
{{B}}第一篇{{/B}}
(2002年理工A级阅读理解考题)

"They" in the second line of the last paragraph refers to ______.

A:old New England fences B:the stretch of walled fields C:the expedition members D:ancient villages

{{B}}第三篇{{/B}}

"They" in the second line of the last paragraph refers to ______.

A:old New England fences B:the stretch of walled fields C:the expedition members D:ancient villages