新四级听力听写练习第四单元Lesson18（在线收听）

Welcome to the Bottom of the World

Antarctica is the highest, driest, and coldest place on Earth. It is also the remotest, a fact which accounts for its unspoiled environment. It is difficult for people to get there, and not a comfortable place for people to stay once they arrive. It is widely described as the last true wilderness on our planet.

The Antarctic continent has mountain ranges similar in size to the European Alps. But whereas the Alps' snowcaps are just deep enough for skiing, Antarctic mountains are swallowed up by their caps, and lie buried beneath an ice sheet that is five kilometers thick.

The cold climate is responsible for maintaining the continent's year-round ice fields: They never melt. Even though Antarctica receives more sunlight than the equator, the temperatures are lower because the ice sheet reflects the heat back into space. Thus, the coldest temperature ever recorded on Earth was in Antarctica in July, 1983: Soviet scientists shivered through temperatures that fell to minus 89.2 degrees Celsius.

For centuries, Europeans wondered about the existence of a South-Polar continent, but no one actually knew for certain Antarctica was there until 1820 when European explorers "discovered" it. Since then, men have gone to Antarctica in search of adventure. Testing their abilities, several teams of explorers set out in 1911 to be the first men to stand at the South Pole. Norwegian Roald Amundsen and his men reached the pole; so did Robert F. Scott, an Englishman, but he and his team died on the return trip.

Once completely inaccessible, Antarctica has more recently been playing host to adventurers seeking excitement, scientists interested in experimenting, and companies looking to exploit this wild terrain for profit: gold, uranium, and oil are just some of the valuable resources which lie beneath the continent's icy covering.

Though no human population is native to Antarctica, about 1,000 people work there in the summer months, and another 12,000 tourists visit every year. They come to enjoy the unspoiled environment, the bright blue skies, and the fresh white snow fields.

If a tourist is lucky enough, he or she can join an expedition to see some of the continent's other residents. Animals along the coast of the Southern Ocean don't mind the cold weather, and thrive in Antarctica's seas. Penguins and seals breed on the icy shores and fish for krill in the cool water.

Yet, Antarctica's fragile and complicated eco-system is threatened by its human visitors. Damage to the environment occurs as people come looking for resources beneath the ice, or carelessly leave their garbage behind. Currently, countries are working to ensure that the damage to Antarctica's environment is minimized, and that the last wilderness on Earth will remain an unspoiled place.