2 . To understand the effect of ice melting (融化) around the world we first have to understand what an ice sheet actually is. Covering 5.4 million square miles in Antarctica (南极洲) and 656,000 square miles in Greenland, an ice sheet is actually a huge land of ice from the Ice Age. These sheets form in areas where snow that falls in winter does not melt entirely over the summer. This ice, home to different species of animals, is now melting at a rate that cannot support the life it currently holds.

Many of these creatures rely on ice sheets as land for resting, hunting and protection, yet as the size decreases, they are forced out of their homeland in search of other land on which to live. Often this means journeys to search for food and an imbalanced ecosystem happens when different species are forced together onto the coast.

Since the 1990s, the deer population has dropped by 56 per cent—climate change has caused warmer temperatures over winter setting off rainfall instead of snow, which freezes more quickly underfoot and makes it harder to walk and search for food. In the summer, frozen layers of land melts and releases trapped diseases which bring death to animals. A similar situation has fallen on the polar bears who suffered a 40 per cent population loss between 2001—2010.

Quite apart from these problems, the threat of sea levels rising if the ice caps were to disappear is approaching. If the Greenland Ice Sheet melted, the sea level would rise around six meters, and if the Antarctic Ice Sheet melted, sea levels would rise by around 20 feet. As a matter of fact, sea levels have risen about eight inches since 1880, three of which we’ve gained over the last 25 years. This seemingly small amount has already caused dangerous flooding, loss of farmland and more deadly storms.

While we’re still a long way from losing the ice sheets all together, we’ve already lost too much and if we don’t take climate change seriously now, we will certainly hit the point of no return.

1. What is an ice sheet according to the passage?

A．It is an area where ice never melts in summer.

B．It is a land of ice that covers all Greenland.

C．It is a large area of ice that exists for centuries.

D．It is an ice world for animals to live on.

2. How does the melting of ice sheets affect animals?

A．It makes it easier to travel to other land.

B．It increases the population of sea animals.

C．It makes their surroundings more comfortable.

D．It causes hunger and illness among animals.

3. What can we infer from Paragraph 4?

A．Ice sheet will soon disappear from the Earth.

B．Sea levels are rising faster in recent years.

C．Greenland will be the first to lose all its ice.

D．All natural disasters happen due to sea level rise.

4. What could be the best title for this passage?

A．Effect of Melting Ice Sheets	B．Ice, Sea and Animals
C．Greenland and Antarctica	D．Changes of Sea Levels

3 . Researchers have solved a long-standing mystery: why rocks on a flat lakebed in Death Valley National Park in California sometimes move. Racetrack Playa, the waterless lakebed, is named for the long trails (痕迹) that the rocks, some of which weigh hundreds of pounds, leave in the earth.

What was one of the world’s natural wonders now appears to be the perfect combination of rain, wind, ice and sun, scientists have found. Dr. Norris and James M. Norris, a cousin and co-author, actually saw the rocks moving in December when they went to check on the project.

For their study, they used special global positioning system tools, designed by James Norris, in rocks of various sizes brought from outside the park. They were not allowed to move or change anything of the existing playa (盐湖) stones.

No river flows into the playa, though rainwater sometimes fills part of it to a depth of a few inches. It’s when this happens, and the nights are below freezing and the days are fine, that the rocks may “sail”, the researchers said. On those occasions, the cold night air leaves a sheet (薄片) of ice only an eighth of an inch thick. Then the warmth of the sun causes the sheet to break up. As more ice melts (融化), some of these lesser sheets have room to move. Driven by light winds, the sheets push up against rocks. The wind drives the water, too, which also helps push the ice to some degree. The movement is slow, no more than about 15 feet a minute.

The movements are episodic — the conditions may be just right for a few minutes, and then the sun causes more ice to break and the movement stops. And once the water disappears, it may be years before the rocks move again, even if the playa floods again, because the right temperature and wind conditions may not occur.

1. What do we know about Racetrack Playa?

A．It has flat rocks in the earth.	B．It is covered by rocks.
C．It has some valleys.	D．It is usually dry.

2. What was the park’s attitude to using GPS in the lakebed’s stones?

A．It doubted the method.	B．It was against doing so.
C．It felt it was worth a try.	D．It thought it was useless.

3. Why do the stones “sail” according to the Norrises?

A．They are moved by big floods.

B．They move just because of strong winds.

C．They are mainly pushed by wind-driven ice.

D．They move very slowly on smooth ice sheets.

4. What does the underlined word “episodic” in the last paragraph probably mean?

A．Amazingly big.	B．Extremely slow.
C．Happening sometimes.	D．Going on without stopping.

4 . Spend any time in London, England’s capital, and you’ll quickly gather that it’s a multicultural (多元文化的) community. Look around at your fellow passengers on the Tube(地铁) or the bus. They’re of every skin color and dress differently to one another. Listen, and you’ll hear many other languages besides English spoken. Some of these people, no doubt, will be tourists who are in London to see the sights. But others — in fact probably most — will be living their lives there, along with millions of others.

Along with white British people, there are Britons from, or with parents and grandparents from, the Caribbean, India, China and most other places. This makes London a fascinating place in which to live. The reason is that when people settle in a place, they don’t just buy a house and live there, but bring aspects of the culture of their “old country” with them.

The most visible sign of this is the number of restaurants offering dishes from different parts of the world. In a city in which it’s estimated 250 different languages are spoken, you can expect a similarly wide range of foods to be available. You would expect in one of the world’s leading cities to encounter(遇到) French, Italian, Chinese and Indian eateries. But in London you’ll also find Polish, Patagonian and Palestinian restaurants.

However, London’s multiculturalism isn’t just about food. Many types of people are gathered in one space, but the way they live differently shows in that space. They worship(崇拜) differently, for one thing. Alongside the famous old English churches by Nicholas Hawksmoor and Christopher Wren — responsible for one of the capital’s most famous landmark, St Paul’s Cathedral—you’ll find mosques(清真寺), temples and synagogues (犹太教堂).

London even speaks its own special kind of English. Language experts created the term “Multicultural London English” to identify the dialect of English that appeared at the end of the last century.

All of this makes London a very surprising and varied place to call your home. But, in a way, this has long been true. In the 18^th century, the compiler(编纂者) of the first English dictionary, Samuel Johnson, once said: “ He who is tired of London is tired of life.”

1. By describing the situation on the Tube and bus, the author intends to ________.

A．show that London is a multicultural city

B．explain why London appeals to tourists

C．prove that London is a great place to live in

D．inform us of how the population of Britain is made up

2. According to the article, people who settle in London from other places ________.

A．are forced to give up their native language

B．find it easy to buy a house in the city

C．bring in cultural practices from their original country

D．make up the majority of the population in the city

3. Which of the following could be used as proof of London’s multiculturalism?

A．The city is home to the famous building St Paul’s Cathedral.

B．The city has become a favorite destination for tourists abroad.

C．There are a variety of French restaurants in the city.

D．A new London dialect has appeared in recent years.

4. Samuel Johnson is mentioned in the last paragraph to ________.

A．show what London was like in the 18th century

B．prove the cultural diversity of London from a historical aspect

C．inform the readers what to expect in London

D．introduce the first English dictionary he compiled