1 . 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.

2 . In the spring and summer months, thunderstorms are common.     1     In thunderstorms, lightning can strike people and buildings and is very dangerous.

It was reported that a man was struck by lightning when he was making a phone call under a tree. He died at once. You may not know it, but nearly 1,800 thunderstorms are happening at any moment around the world.     2     So what should you do during a lightning storm? Scientists say that a person’s chances of   being struck by lightning are 1 in 600,000.     3    

If you are indoors during a thunderstorm:

*Stay away from anything that is metal because lightning can come into the house through it.

*Don’t stand near the windows.

*Don’t take a shower or bath. Lightning can travel through water.

* Never use the phone.       4    

If you are caught in a thunderstorm outdoors:

*     5     If there’s no building around, try to find a low place to stay in.

*Do not go under a tree because the lightning could hit the tree and travel through the tree to hit you.

* Never use a cell phone.

3 . Using too much water or throwing rubbish into our rivers are clear ways that humans can put our water supply in danger, but we also affect our water supply in less obvious ways. You may wonder how paving(铺砌) a road can lead to less usable fresh water. A major part of the water we use every day is groundwater. Groundwater does not come from lakes or rivers. It comes from underground. The more roads and parking lots we pave, the less water can flow into the ground to become groundwater.

Human activity is not responsible for all water shortages(缺乏). Drier climates are of course more likely to have droughts(干旱) than areas with more rainfall, but in any case, good management can help to make sure there is enough water to meet our basic needs .

Thinking about the way we use water every day can make a big difference, too. In the United States, a family of four can use 1.5 tons of water a day! This shows how much we depend on water to live, but there’s a lot we can do to lower the number.

You can take steps to save water in your home. To start with, use the same glass for your drinking water all day. Wash it only once a day. Run your dishwasher only when it is full. Help your parents fix any leaks(滴水) in your home. You can even help to keep our water supply clean by recycling batteries instead of throwing them away.

4 . I shall never forget the day when the earthquake happened. It was about 5 in the afternoon and I was _________ along the road to my daughter’s school. Our plan was to go_________ together. I stopped at a_________ to get some fresh fruit. We liked to have some fruit to eat after our swim. I was driving along a high_________ on my way to the school. _________ my road was another road which was built like a_________. I was_________ so I put the bag of apples_________ me and started to eat one. Suddenly I saw the cars in front of me start to_________ from side to side. I slowed down. Then my car started to shake! I didn’t know what was happening. Perhaps something had__________ wrong with my car. I drove a little more slowly and then I__________ the car and at the same moment the road__________ onto the cars in front of me. I found myself in the__________. I couldn’t move. My legs and feet were hurt badly and I couldn’t move them. All around me was__________. But below me I could hear shouts and a lot of noises.

Then I realized what had happened. I had been__________ an earthquake. For about two hours nobody came. Luckily I could reach the bag of__________，so at least I had plenty to eat. Then I heard people__________ towards me. A team of people had come to__________ if anyone was under the__________ road. I called out, “I'm here！” I heard a shout. Soon a stranger climbed to my car. “How are you__________？” he asked. “Not too bad,” I said. They didn’t get me out until the next morning.

6 . A company in San Francisco, California, has found a way to turn used plastic bottles into women's shoes. Every day, millions of Americans drink water and other liquids from plastic bottles. More than 60 million of them are thrown away each day. Many of the plastic bottles end up in landfills or are burned with other waste products.

A San Francisco-based company called Rothy's, however, turns this plastic waste into environmentally friendly shoes. Roth Martin is the company's co-founder. He explains how they turn plastic into soft material for women's feet. They take plastic, clean it, and break it down into small pieces. Then they press them through a device that makes soft fibers. Those fibers are then bonded together. This is done by a 3-D machine. It is designed to reduce waste while people are making the shoes. The knitted stuff and the inner part of the shoe are then attached to the shoe's outer part called the sole（鞋底）. This outer sole is also made from environmentally friendly material: responsibly sourced no-carbon rubber.

Rothy's shoes are sold online. They are flat shoes, with either a rounded or pointed toe. They come in different colors and designs. They cost either $ 125 or $ 145 per pair, depending on the design. After American actress Gwyneth Paltrow discovered them, the demand for the shoes grew. Martin says there is no shortage of material to fill that demand. “We're not going to run out of water bottles any time soon, so we have a limitless supply of material, and I think that is a good sign for our future.” When the environmentally friendly shoes wear out, customers can return them at no cost to a company that uses the recycled material to make other products.

For now, the shoes are only available to be shipped in the United States. However, the company says it will add international shops in the near future.

9 . This is the story of three plastic bottles, empty and abandoned. Their journeys are about to diverge, more or less influencing the fate of our planet.

Bottle One, like hundreds of millions of tons of other plastic bottles, ends up in a landfill. This huge dump expands each day as more trash comes in and continues to take up space. As plastics sit there being pressed among layers of their junk, rainwater flows through the waste and absorbs the chemicals it contains, and some of those are highly poisonous. Together they create harmful matter called leachate (沥滤液）, which can move into groundwater, soil and streams, poisoning ecosystems and harming wildlife. It can take Bottle One 1,000 years to rot away.

Bottle Two's journey is strange. He floats on water that reaches a stream, a stream that flows into a river, and a river that reaches the ocean. After months lost at sea, he's slowly drawn where trash accumulates, a place known as the Great Pacific Garbage Patch. Here the ocean's currents have trapped millions of pieces of plastic waste. There the water becomes a cloudy plastic soup. Some animals, like seabirds, get stuck in the mess. They, and others, mistake the brightly colored plastic things for food. Plastic makes them feel full when they're not, so they starve to death and pass the poisons from the plastic up the food chain. For example, it's eaten by fish, and the fish are eaten by us.

But Bottle Three is spared the cruel suffering of his brothers. A truck brings him to a plant where he and his companions are squeezed flat and pressed into a block. The blocks are cut and torn into tiny pieces, which are washed and melted, so they become the raw materials that can be used again. As if by magic, Bottle Three is now ready to be reborn as something completely new.

For this bit of plastic with such humble origins, suddenly the sky is the limit.

10 . Foxes have become a part of life in Britain's urban areas.They are striking creatures but they are also dangerous.Three years ago，twin baby girls Isabella and Lola Koupparis were left with arm and face injuries after they were attacked by a fox while they were sleeping at their home.Last week，four-­week­-old baby boy Denny Dolan was bitten by a fox which entered his home.After gaining access to the home through the front door，the fox pulled the baby down from the sofa and tried to drag him outside，biting him and almost severing(割断) his finger.

Although fox attacks on humans are still very rare，they will become more common if we don't change our behavior towards these increasingly fearless animals.It is humans rather than foxes that are responsible for rising fox attacks on humans.

On the one hand，people who love foxes treat these wild animals like pets，leaving food out for foxes，feeding them from their hands，and even inviting foxes into their home.The result is that the fox is more brazen(厚颜无耻的)and less inclined to avoid us.It is those people who feed foxes that cause foxes to lose their fear of humans.However，as long as they have a healthy fear of humans，they won't bother humans.

On the other hand，foxes have moved into cities for lack of resources in rural areas.We take away their natural habitat to build more houses and factories.Foxes have no choice but to live and search for food in the city.If they live in the forest，no fox attack will happen.

We have to learn to share the earth with animals and let foxes return to their natural habitat.We also have to learn to look upon foxes as wild animals.We have to remember that they are instinctive killers，efficient and silent with only one purpose，kill to eat.We must certainly not intervene them，even when they look starved.They are hungry for a reason.The hunger will force them to hunt for rabbits and other animals instead of waiting for food at your door.