1 . Are you facing a situation that looks impossible to fix?

In 1969,the pollution was terrible along the Cuyahoga River Cleveland, Ohio. It    1    (be) unimaginable that it could ever be cleaned up. The river was so polluted that it    2    (actual) caught fire and burned. Now, years later, this river is one of    3    most outstanding（杰出的）examples of environmental cleanup.

But the river wasn’t changed in a few days    4    even a few months. It took years of work     5    (reduce) the industrial pollution and clean the water. Finally, that hard work paid off and now the water in the river is    6    (clean) than ever.

Maybe you are facing an impossible situation. Maybe you have a habit    7    is driving your family crazy. Possibly you drink too much or don’t know how to control your credit card use. When you face such an impossible situation, don’t you want a quick fix and something to change immediately?

While there are    8    (amaze) stories of instant transformation, for most of us the    9    (change) are gradual and require a lot of effort and work, like cleaning up a polluted river. Just be     10    (patience).

3 . 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.

6 . Earth Hour is organized by the World Wide Fund for Nature. It's a big event usually at the end of March every year. On this evening, people “go dark”.     1    

It's true that turning off lights for just one hour saves only a small amount of power.    2    On one level, joining in Earth Hour makes people think about the problem of climate change and what we can do in everyday life to protect nature.

But on another level, a large number of people’s acting together sends a powerful message to governments and companies.     3     They begin considering green issues when big decisions.

The logo(标识) of Earth Hour is “60+” .The number 60 is for the 60 minutes of Earth Hour.     4     In fact, people who join in Earth Hour say that taking part makes them want to do more for the environment.

    5     Musicians give concerts by playing acoustic(原声的) instruments instead of electric ones, and using candles instead of electric lights. Celebrity chefs have created special recipes for families to prepare and eat by candlelight. Tree-planting sessions, group walks and runs are also among the options.

Polar bears are undergoing hunger in a world     1     (warm) than ever before.

Polar bears live in the environment too cold for most animals. For most of the year, they live and hunt on Arctic sea ice. Nature has prepared     2     (they) for the cold conditions. But nothing has prepared the bears for the danger     3     threatens their only home.

Polar bears’ world is melting. Studies show that polar ice     4     (reduce) by 9.8% every 10 years since 1978. Now about 20,000 to 25,000 polar bears live in the Arctic. Polar bears depend     5     sea ice for their     6     (survive). “Sea ice is more than just the platform that the bears walk over,” says Andrew Derocher,     7     scientist who studies North American polar bear populations. “Without it, they can’t exist.”

    8     (melt) and refreezing of polar ice is natural. But in a warmer world, the cycle speeds up, and polar bears have less time     9     (hunt). Normally, they have three months in the spring when they gain more weight. The extra fat will be used, when the bears are not     10     (active) hunting.

9 . How to Reduce Gift Wrap Waste

Wrapping paper may have “paper” in its name, but that doesn’t automatically mean it can be recycled.     1     Try these suggestions for cutting down the amount of wrapping paper you throw away.

Reuse what you have.     2     It’s estimated that the U.S. produces 4.6 million pounds of wrapping paper annually, and 2.3 million pounds of that stays in people’s homes, awaiting reuse.

Use different materials.     3     Select basic brown thick paper that can be made up with a bow, ribbons, leaves, pinecones or markers. Repurpose newspapers, old posters and children’s school artworks as wrapping paper. There are plenty of other eco-friendly alternatives to wrapping paper that are just delightful and celebratory.

    4     Use baskets, fabric, gift boxes or bags, tea towels, and more to contain and display your presents. Learn the Japanese art of wrapping, using beautiful knots(绳结) to fasten colorful, reusable fabrics in attractive ways. This way, you’ll have no wrapping paper waste to deal with.

Ask for better paper. Shops store what customers want, and recyclability should be a top priority, so let that be known when you’re out shopping. As explained by Simon Ellin, CEO of the Recycling Association, a trade body that represents about 90 waste management companies and paper merchants in the United Kingdom, “It’s a campaign we’ve been on all year — do you really need to design a non-paper wrapping paper? Make paper with recycling in mind!”     5    

10 . My name is Miranda Gibson. I have been at the top of a tree for five months now. Some people might wonder________on earth I would choose to do that.

I have walked through this forest many times. On December 12, 2011, ________rolled into the forest and the destruction (摧毁) began. I couldn’t________the thought that these forests would be________ forever. So, on December 14, 2011, I packed up my life, ________of my job plans, and climbed 60 meters to the top of this tree. I have been here ever since.

Life in the tree top can be________at times. I have times when I feel frustrated (沮丧的) and wish I could________, to anywhere, just have a ________of scenery for a minute! There are times too, when I feel terribly________.I miss my friends and family.________these times, I find myself loving the________.

Living on the tree has been inspiring. I am willing to________ here for as long as it takes,________I honestly hope it won’t be too________before I can put my feet on the ground below and stand in a forest that will never be________.