1 . 阅读下面短文，在空白处填入1个适当的单词或括号内单词的正确形式。

The polar bear is found in the Arctic Circle and some big land masses as far south as Newfoundland. While they are rare north of 88°, there is evidence     1     they range all the way across the Arctic, and as far south as James Bay in Canada. It is difficult to figure out a global population of polar bears as much of the range has been     2    (poor) studied; however, biologists calculate that there are about 20,000-25,000 polar bears worldwide.

Modern methods     3     tracking polar bear populations have been employed only since the mid-1980s, and are expensive     4    (perform) consistently over a large area. In recent years some Inuit people in Nunavut     5    (report) increases in bear sightings around human settlements, leading to a     6    (believe) that populations are increasing. Scientists have responded by     7    (note) that hungry bears may be congregating(聚集) around human settlements, leading to the illusion(错觉) that populations are     8    (high) than they actually are. Of     9     nineteen recognized polar bear subpopulations, three are declining, six     10    (be) stable, one is increasing, and nine lack enough data.

2 . Washington, D.C. Bicycle Tours

Cherry Blossom Bike Tour in Washington, D.C.

Duration: 3 hours

This small group bike tour is a fantastic way to see a world-famous cherry trees with beautiful flowers of Washington, D.C. Your guide will provide a history lesson about the trees and the famous monuments where they blossom. Reserve your spot before availability — the cherry blossoms—disappear!

Washington Capital Monuments Bicycle Tour

Duration: 3 hours (4 miles)

Join a guided bike tour and view some of the most popular monuments in Washington, D.C. Explore the monuments and memorials on the National Mall as your guide shares unique facts and history at each stop. Guided tour includes bike, helmet, cookies and bottled water.

Capital City Bike Tour In Washington, D.C.

Duration: 3 hours

Morning or Afternoon, this bike tour is the perfect tour for D. C. newcomers and locals looking to experience Washington, D.C. in a healthy way with minimum effort. Knowledgeable guides will entertain you with the most, interesting stories about Presidents, Congress, memorials, and parks. Comfortable bikes and a smooth tour route(路线) make cycling between the sites fun and relaxing.

Washington Capital Sites at Night Bicycle Tour

Duration: 3 hours (7miles)

Join a small group bike tour for an evening of exploration in the heart of Washington, D.C. Get up close to the monuments and memorials as you bike the sites of Capitol Hill and the National Mall. Frequent stops are made for photo taking as your guide offers unique facts and history. Tour includes bike, helmet, and bottled water. All riders are equipped with reflective vests and safety lights.

1. Which tour do you need to book in advance?

A．Cherry Blossom Bike Tour in Washington, D.C.

B．Washington Capital Monuments Bicycle Tour.

C．Capital City Bike Tour in Washington.

D．Washington Capital Sites at Night Bicycle Tour.

2. What will you do on the Capital City Bike Tour?

A．Meet famous people.	B．Go to a national park.
C．Visit well-known museums.	D．Enjoy interesting stories.

3. Which of the following does the bicycle tour at night provide?

A．City maps.	B．Cameras.
C．Meals.	D．Safety lights.

3 . Monkeys seem to have a way with numbers.

A team of researchers trained three Rhesus monkeys to associate 26 clearly different symbols consisting of numbers and selective letters with 0-25 drops of water or juice as a reward. The researchers then tested how the monkeys combined—or added—the symbols to get the reward.

Here’s how Harvard Medical School scientist Margaret Livingstone, who led the team, described the experiment: In their cages the monkeys were provided with touch screens. On one part of the screen, a symbol would appear, and on the other side two symbols inside a circle were shown. For example, the number 7 would flash on one side of the screen and the other end would have 9 and 8. If the monkeys touched the left side of the screen they would be rewarded with seven drops of water or juice; if they went for the circle, they would be rewarded with the sum of the numbers—17 in this example.

After running hundreds of tests, the researchers noted that the monkeys would go for the higher values more than half the time, indicating that they were performing a calculation, not just memorizing the value of each combination.

When the team examined the results of the experiment more closely, they noticed that the monkeys tended to underestimate(低估) a sum compared with a single symbol when the two were close in value—sometimes choosing, for example, a 13 over the sum of 8 and 6. The underestimation was systematic: When adding two numbers, the monkeys always paid attention to the larger of the two, and then added only a fraction(小部分) of the smaller number to it.

“This indicates that there is a certain way quantity is represented in their brains, ”Dr. Livingstone says. “But in this experiment what they’re doing is paying more attention to the big number than the little one.”

1. What did the researchers do to the monkeys before testing them?

A．They fed them.	B．They named them.
C．They trained them.	D．They measured them.

2. How did the monkeys get their reward in the experiment?

A．By drawing a circle.	B．By touching a screen.
C．By watching videos.	D．By mixing two drinks.

3. What did Livingstone’s team find about the monkeys?

A．They could perform basic addition.	B．They could understand simple words.
C．They could memorize numbers easily.	D．They could hold their attention for long.

4. In which section of a newspaper may this text appear?

A．Entertainment.

B．Health.

C．Education.

D．Science.

4 . California has lost half its big trees since the 1930s, according to a study to be published Tuesday and climate change seems to be a major factor(因素).

The number of trees larger than two feet across has declined by 50 percent on more than 46, 000 square miles of California forests, the new study finds. No area was spared or unaffected, from the foggy northern coast to the Sierra Nevada Mountains to the San Gabriels above Los Angeles. In the Sierra high country, the number of big trees has fallen by more than 55 percent; in parts of southern California the decline was nearly 75 percent.

Many factors contributed to the decline, said Patrick McIntyre, an ecologist who was the lead author of the study. Woodcutters targeted big trees. Housing development pushed into the woods. Aggressive wildfire control has left California forests crowded with small trees that compete with big trees for resources(资源).

But in comparing a study of California forests done in the 1920s and 1930s with another one between 2001 and 2010, McIntyre and his colleagues documented a widespread death of big trees that was evident even in wildlands protected from woodcutting or development.

The loss of big trees was greatest in areas where trees had suffered the greatest water shortage. The researchers figured out water stress with a computer model that calculated how much water trees were getting in comparison with how much they needed, taking into account such things as rainfall, air temperature, dampness of soil, and the timing of snowmelt(融雪).

Since the 1930s, McIntyre said, the biggest factors driving up water stress in the state have been rising temperatures, which cause trees to lose more water to the air, and earlier snowmelt, which reduces the water supply available to trees during the dry season.

1. What is the second paragraph mainly about?

A．The seriousness of big-tree loss in California.

B．The increasing variety of California big trees.

C．The distribution of big trees in California forests.

D．The influence of farming on big trees in California.

2. Which of the following is well-intentioned but may be bad for big trees?

A．Ecological studies of forests.

B．Banning woodcutting.

C．Limiting housing development.

D．Fire control measures.

3. What is a major cause of the water shortage according to McIntyre?

A．Inadequate snowmelt.	B．A longer dry season.
C．A warmer climate.	D．Dampness of the air.

4. What can be a suitable title for the text?

A．California’s Forests: Where Have All the Big Trees Gone?

B．Cutting of Big Trees to Be Prohibited in California Soon

C．Why Are the Big Trees Important to California Forests?

D．Patrick McIntyre: Grow More Big Trees in California

5 . Steven Stein likes to follow garbage trucks. His strange habit makes sense when you consider that he’s an environmental scientist who studies how to reduce litter, including things that fall off garbage trucks as they drive down the road. What is even more interesting is that one of Stein’s jobs is defending an industry behind the plastic shopping bags.

Americans use more than 100 billion thin film plastic bags every year. So many end up in tree branches or along highways that a growing number of cities do not allow them at checkouts(收银台). The bags are prohibited in some 90 cities in California, including Los Angeles. Eyeing these headwinds, plastic-bag makers are hiring scientists like Stein to make the case that their products are not as bad for the planet as most people assume.

Among the bag makers’ argument: many cities with bans still allow shoppers to purchase paper bags, which are easily recycled but require more energy to produce and transport. And while plastic bags may be ugly to look at, they represent a small percentage of all garbage on the ground today.

The industry has also taken aim at the product that has appeared as its replacement: reusable shopping bags. The stronger a reusable bag is, the longer its life and the more plastic-bag use it cancels out. However, longer-lasting reusable bags often require more energy to make. One study found that a cotton bag must be used at least 131 times to be better for the planet than plastic.

Environmentalists don’t dispute(质疑) these points. They hope paper bags will be banned someday too and want shoppers to use the same reusable bags for years.

1. What has Steven Stein been hired to do?

A．Help increase grocery sales.

B．Recycle the waste material.

C．Stop things falling off trucks.

D．Argue for the use of plastic bags.

2. What does the word “headwinds” in paragraph 2 refer to?

A．Bans on plastic bags.

B．Effects of city development.

C．Headaches caused by garbage.

D．Plastic bags hung in trees.

3. What is a disadvantage of reusable bags according to plastic-bag makers?

A．They are quite expensive.

B．Replacing them can be difficult.

C．They are less strong than plastic bags.

D．Producing them requires more energy.

4. What is the best title for the text?

A．Plastic, Paper or Neither

B．Industry, Pollution and Environment

C．Recycle or Throw Away

D．Garbage Collection and Waste Control

6 . When a leafy plant is under attack, it doesn’t sit quietly. Back in 1983, two scientists, Jack Schultz and Ian Baldwin, reported that young maple trees getting bitten by insects send out a particular smell that neighboring plants can get. These chemicals come from the injured parts of the plant and seem to be an alarm. What the plants pump through the air is a mixture of chemicals known as volatile organic compounds, VOCs for short.

Scientists have found that all kinds of plants give out VOCs when being attacked. It’s a plant’s way of crying out. But is anyone listening? Apparently. Because we can watch the neighbours react.

Some plants pump out smelly chemicals to keep insects away. But others do double duty. They pump out perfumes designed to attract different insects who are natural enemies to the attackers. Once they arrive, the tables are turned. The attacker who was lunching now becomes lunch.

In study after study, it appears that these chemical conversations help the neighbors .The damage is usually more serious on the first plant, but the neighbors, relatively speaking, stay safer because they heard the alarm and knew what to do.

Does this mean that plants talk to each other? Scientists don’t know. Maybe the first plant just made a cry of pain or was sending a message to its own branches, and so, in effect, was talking to itself. Perhaps the neighbors just happened to “overhear” the cry. So information was exchanged, but it wasn’t a true, intentional back and forth. Charles Darwin, over 150 years ago, imagined a world far busier, noisier and more intimate (亲密的) than the world we can see and hear. Our senses are weak. There’s a whole lot going on.

1. What does a plant do when it is under attack?

A．It makes noises.	B．It gets help from other plants.
C．It stands quietly	D．It sends out certain chemicals.

2. What does the author mean by “the tables are turned” in paragraph 3?

A．The attackers get attacked.

B．The insects gather under the table.

C．The plants get ready to fight back.

D．The perfumes attract natural enemies.

3. Scientists find from their studies that plants can ________.

A．predict natural disasters

B．protect themselves against insects

C．talk to one another intentionally

D．help their neighbors when necessary

4. What can we infer from the last paragraph?

A．The world is changing faster than ever.

B．People have stronger senses than before

C．The world is more complex than it seems

D．People in Darwin’s time were imaginative.

7 . 阅读下面的短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空。

Chengdu has dozens of new millionaires, Asia’s biggest building, and fancy new hotels. But for tourists like me, pandas are its top     1    (attract).

So it was a great honour to be invited backstage at the not-for-profit Panda Base, where ticket money helps pay for research. I     2    (allow) to get up close to these cute animals at the 600-acre centre. From tomorrow, I will be their UK ambassador. The title will be     3    (official) given to me at a ceremony in London. But my connection with pandas goes back     4     my days on a TV show in the mid-1980s,     5     I was the first Western TV reporter     6    (permit) to film a special unit caring for pandas rescued from starvation in the wild. My ambassadorial duties will include     7    (introduce) British visitors to the 120-plus pandas at Chengdu and others at a research centre in the misty mountains of Bifengxia.

On my recent visit, I held a lively three-month-old twin that had been rejected by     8    (it) mother. The nursery team switches him every few     9    (day) with his sister so that while one is being bottle-fed,     10     other is with mum—she never suspects.

8 . 阅读下面短文，在空白处填入 1个适当的单词或括号内单词的正确形式。

The giant panda     1     (love) by people throughout the world. Chinese scientists     2     (recent) had a chance to study a wild female panda with a newborn baby. She was a very     3    (care) mother. For 25days, she never left her baby, not even to find something     4     (eat)! She would not let any other pandas come near. She licked the baby constantly to keep it clean. Any smell might attract natural     5    (enemy) that would try to eat the little comforting panda. The mother held the baby in her front paws much the way a human does.     6     it cried, she rocked it back and forth and gave it little comforting pats. The mother continued to care for the young panda     7     more than two years. By that time, the panda no longer needed     8    (it) mother for food. However, it stayed with her and learned about the ways of the forest. Then, after two and a half years, the mother     9     (drive) the young panda away. It was time for her to have a new baby,     10     it was also time for the young panda to be independent.

9 . By the end of the century，if not sooner，the world’s oceans will be bluer and greener thanks to a warming climate，according to a new study.

At the heart of the phenomenon lie tiny marine microorganisms(海洋微生物) called phytoplankton. Because of the way light reflects off the organisms，these phytoplankton create colourful patterns at the ocean surface. Ocean colour varies from green to blue，depending on the type and concentration of phytoplankton. Climate change will fuel the growth of phytoplankton in some areas，while reducing it in other spots，leading to changes in the ocean's appearance.

Phytoplankton live at the ocean surface，where they pull carbon dioxide(二氧化碳) into the ocean while giving off oxygen. When these organisms die，they bury carbon in the deep ocean，an important process that helps to regulate the global climate. But phytoplankton are vulnerable to the ocean's warming trend. Warming changes key characteristics of the ocean and can affect phytoplankton growth，since they need not only sunlight and carbon dioxide to grow，but also nutrients.

Stephanie Dutkiewicz，a scientist in MIT's Center for Global Change Science，built a climate model that projects changes to the oceans throughout the century. In a world that warms up by 3℃，it found that multiple changes to the colour of the oceans would occur. The model projects that currently blue areas with little phytoplankton could become even bluer. But in some waters，such as those of the Arctic，a warming will make conditions riper for phytoplankton，and these areas will turn greener. “Not only are the quantities of phytoplankton in the ocean changing. ”she said，“but the type of phytoplankton is changing. ”

1. What are the first two paragraphs mainly about?

A．The various patterns at the ocean surface.

B．The cause of the changes in ocean colour.

C．The way light reflects off marine organisms.

D．The efforts to fuel the growth of phytoplankton.

2. What does the underlined word “vulnerable” in Paragraph 3 probably mean?

A．Sensitive.	B．Beneficial
C．Significant	D．Unnoticeable

3. What can we learn from the passage?

A．Phytoplankton play a declining role in the marine ecosystem.

B．Dutkiewicz's model aims to project phytoplankton changes

C．Phytoplankton have been used to control global climate

D．Oceans with more phytoplankton may appear greener.

4. What is the main purpose of the passage？

A．To assess the consequences of ocean colour changes

B．To analyse the composition of the ocean food chain

C．To explain the effects of climate change on oceans

D．To introduce a new method to study phytoplankton

10 . After years of heated debate, gray wolves were reintroduced to Yellowstone National Park. Fourteen wolves were caught in Canada and transported to the park. By last year, the Yellowstone wolf population had grown to more than 170 wolves.

Gray wolves once were seen here and there in the Yellowstone area and much of the continental United States, but they were gradually displaced by human development. By the 1920s, wolves had practically disappeared from the Yellowstone area. They went farther north into the deep forests of Canada, where there were fewer humans around.

The disappearance of the wolves had many unexpected results. Deer and elk populations — major food sources (来源) for the wolf — grew rapidly. These animals consumed large amounts of vegetation (植被), which reduced plant diversity in the park. In the absence of wolves, coyote populations also grew quickly. The coyotes killed a large percentage of the park’s red foxes, and completely drove away the park’s beavers.

As early as 1966, biologists asked the government to consider reintroducing wolves to Yellowstone Park. They hoped that wolves would be able to control the elk and coyote problems. Many farmers opposed the plan because they feared that wolves would kill their farm animals or pets.

The government spent nearly 30 years coming up with a plan to reintroduce the wolvers. The U.S. Fish and Wildlife Service carefully monitors and manages the wolf packs in Yellowstone. Today, the debate continues over how well the gray wolf is fitting in at Yellowstone. Elk, deer, and coyote populations are down, while beavers and red foxes have made a comeback. The Yellowstone wolf project has been a valuable experiment to help biologists decide whether to reintroduce wolves to other parts of the country as well.

1. What is the text mainly about?

A．Wildlife research in the United States.

B．Plant diversity in the Yellowstone area.

C．The conflict between farmers and gray wolves.

D．The reintroduction of wolves to Yellowstone Park.

2. What did the disappearance of gray wolves bring about?

A．Damage to local ecology.

B．Preservation of vegetation.

C．A decline in the park’s income.

D．An increase in the variety of animals.

3. What is the author’s attitude towards the Yellowstone wolf project?

A．Doubtful.

B．Uncaring.

C．Positive.

D．Disapproving.