Polar bears live in the coldest environments on Earth-the Arctic. Called "ice bears" in many
European languages, polar bears depend on the ice that surrounds them for their survival. As the
Arctic climate changes and the ice slowly disappears, polar bears face an increasingly uncertain
future.
Polar bears impress us with their incredible size, power and ability to survive in the cold Arctic.
These giants can stand three meters tall and weigh over 500kg, and they spend their lives traveling
throughout the Arctic. Two layers of fur keep them warm. Interestingly,the hairs are hollow in order
to direct the sunlight straight to the skin. Undemeath their fur, polar bears have an
additional l0-cm-layer of fat.
Polar bears hunt ringed seals (环斑海豹), which live under the Arctic ice. They wait patiently
for hours beside holes in the ice pack (浮冰群) for seals to surface and breathe. Using their great
strength , the bears pull the heavy animals up onto the ice. The seals provide much of the fat the
bears need for warmth.
Since 2006 , polar bears have been labeled a vulnerable (脆弱的) species. Most experts feel
the threat to polar bears comes not from hunters or predators(食肉动物),but from the gradual melting
of Arctic ice. Due to global climate change, the Arctic region is getting warmer. Arctic ice is breaking
up earlier in the spring, and its area is decreasing.
Problems polar bears around Canada"s Hudson Bay are facing may indicate what lies ahead for
polar bears elsewhere. Hudson Bay is located at the southern limit of the polar bears" territory(领地) .
Currently,the ice there breaks up three weeks earlier in the spring than it did 20 years ago. Polar
bears on Hudson Bay fast during the summer,waiting for ice to form in the fall to hunt. Every year,the
Summer gets longer, and the bears get skinner. Over the past 25 years, the average weight of the
female bears has dropped 68kg. This loss affects their ability to reproduce, and already the number
of births has dropped 15% . Unless the bears can leam to survive global climate change, the giants
of the ice may one day disappear.
Earlier this month, the Obama Administration called for increasing protection of the world"s most
southern continent, Antarctica. Scientists say climate change and human activities have increasingly led
to the melting of massive pieces of Antarctic ice. The disappearance of ice will not only affect wildlife
in the area such as seals and penguins. The melting will also cause oceans and seas around the world
to rise.
This represents a major threat, especially to coastal areas. For example, the ancient city of Venice,
Italy has long been threatened by rising sea levels. The situation is made worse by the fact that its
ancient buildings, built on a body of water called a lagoon(淡水湖), are slowly sinking. When the city
was founded about 1,600 years ago, the level of the Adriatic Sea was almost two meters lower than it
is today.
Rising sea levels are not the only threat. The salty water is also destroying Venice"s famous buildings
and artworks. The Italian government is trying to fix the problem with the construction of a
seven-billion-dollar system of moving flood barriers.
Climate change is also leading to the melting of ice in other areas, such as Mount Kilimanjaro in
northeastern Tanzania. It is the highest point in Africa, measuring almost 6,000 meters. The mountain
supports five vegetation zones and many kinds of animals.
The ice glaciers on the mountain are disappearing very quickly. This will have a bad effect on the
mountain"s ecosystems and on Tanzania"s travel industry. Also, a valuable record of thousands of years
of weather history will also be lost if the ice melts. Scientists study pieces of glaciers to understand
weather patterns from thousands of years ago.
In the United States, the icy masses in Glacier National Park in Montana may soon completely
disappear because of climate change. In 1850, it is estimated that there were 150 glaciers in the more
than 400,000 hectare park.
There are 26 glaciers remaining today. Scientists estimate that the glaciers will be gone by 2030.
Warming temperatures are also threatening the many kinds of plants and animals that live in this mountain
ecosystem.
1. The writer developed the passage mainly by ______.
A. giving examples
B. listing reasons
C. making comparisons
D. using quotations
2. How many glaciers have disappeared since 1850 in Glacier National Park?
A. 150.
B. 26.
C. 400,000.
D. About 124.
3. According to the passage, what has been affected in Italy by rising sea levels?
A. Many kinds of plants and animals died out in Italy.
B. Venice"s famous buildings and artworks are being destroyed completely.
C. The ice glaciers on the mountain are disappearing very quickly.
D. Its ancient buildings could be drowned.
4. What could be the best title for the passage?
A. Climate Change
B. The Melting of Massive Pieces of Antarctic Ice
C. Visiting Endangered Places around the World
D. The disappearing of the Ice Glaciers
© 2017-2019 超级试练试题库,All Rights Reserved.