2 . I fell in love with Yosemite National Park the first time I saw it. My parents took us there for camping. On the way out, I asked them to wait while I ran up to El Capitain, a_________rock of 3,300 feet straight up. I touched that giant rock and knew_________I wanted to climb it. That has been my life’s passion(热爱) ever since—_________the rocks and mountains of Yosemite. I’ve long made Yosemite my_________.

About 15 years ago I started seeing a lot of_________, like beer cans, empty boxes, around the area. It’s beyond me why visitors started respecting the place_________and treated such a beautiful home-like place this way.

I tried_________trash(垃圾) myself, but the job was too big. I would_________an hour or two on the job, only to find the area trashed all over again weeks later. Finally, I got so tired of it that I decided something had to change.

In 2004, together with some climbers, I set a date for a_________. On that day, more than 300 people__________. Over three days we collected about 6,000 pounds of trash. It was amazing how much we were able to__________. I couldn’t believe the__________we made—the park looked clean!

Each year volunteers come for the cleanup from everywhere. In 2007 alone, 2,945 people picked up 42,330 pounds of trash.

I often hear people__________about their surroundings. If you are one of them, I would say the only way to change things is by__________rather than complaining. We need to teach by__________.

4 . Should We Create More National Parks to Save Endangered Animals?

Don’t you find it worrying that more and more species of animals are in real danger of becoming extinct?     1     And I think the best way to do this is for governments to create more national parks.

    2     If this environment is destroyed — for example, when farmers clear a forest for new fields, or trees are cut down to make profits — many animals are unable to survive, and more species are likely to become extinct.

On the other hand, some people fight against the creation of national parks because they consider it is wrong to interfere with nature. They believe that wild animals are happier living in their natural environment.     4     They also point out that a few species are more likely to produce young animals in the wild than in national parks.

All in all, these disadvantages are far less important than the benefits of national parks.     5     As a matter of fact, they protect animals from their greatest enemies, that is, human beings.

5 . In a county of Britain, a pair of pig farmers has managed to feed one million bees by turning over half of their land to wildflowers. Four years ago, brothers Mark and Paul Hayward decided to fill 81 acres of their farm land with wildflowers. This week, a study found they were feeding one million bees at any time.

“This was our target when we started, to, grow enough flowers to feed a million bees on a single day.” Mark said. “We are acutely aware that bees are under threat from modern farming methods and that East England is one of the worst places where bees are seriously suffering from lack of wildflower diversity,” he continued.

“Every third bite of food you eat can come from bees and we wanted to create an operation on our farm that did not push nature out but rather hugged it-as a central part of our ecology system and our food cycle,” he said.

The farm uses all kinds of seeds which can produce many different wild plants and of course, the bees can get food from different wildflowers.

“We are taking a very small role in helping society restore a balance and this starts with plant diversity to encourage insects, bees, small mammals(哺乳动物), and birds,” said Paul. “At the end of the day, we see ourselves as caretakers of this land. Between us we have six children and we owe it to them to farm sustainability(持续性)and set an example for the generations to come,” added Paul.

According to the Bee Conservation Trust, many types of bees have seen their populations decline by 70%, and two species have become extinct in the last century.

Gill Perkins, CEO of the Bee Conservation Trust said, “Thanks to Mark and Paul, at least here, a million bees can keep living, which is of great significance for ourselves now and future.”

6 . A method to transform a commonly thrown-away plastic to a resin (树脂) used in 3D printing could allow for making better use of plastic waste. A team of Washington State University researchers developed a simple and efficient way to transform polylactic acid (PLA)(聚乳酸), a bio-based plastic used in products such as filament, plastic silverware and food packaging to a high-quality resin.

“We found a way to immediately turn this into something that’s stronger and better, and we hope that will provide people the inspiration to upcycle this stuff instead of just throw it away,” said Yu-Chung Chang, a postdoctoral researcher in the WSU School of Mechanical and Materials Engineering and a co-corresponding author on the work. “We made stronger materials just straight out of trash. We believe this could be a great opportunity.”

Although it’s bio-based, PLA, which is categorized as a number 7 plastic, doesn’t break down easily. It can float in fresh or salt water for a year without degrading (降解). It is also rarely recycled because like many plastics, when it’s melted down and re-formed, it doesn’t perform as well as the original version and becomes less valuable.

“It’s biodegradable and compostable, but once you look into it, it turns out that it can take up to 100 years for it to rot away in a landfill,” Chang said. “In reality, it still creates a lot of pollution. We want to make sure that when we do start producing PLA on the milliontons scale, we will know how to deal with it.”

While the researchers focused on PLA for the study, they hope to apply the work to poly-ethylene terephthalate (PET) (涤纶树脂), which is more common than PLA and has a similar chemical structure and presents a bigger waste problem. They have filed a temporary patent and are working to further optimize (优化) the process. The researchers are also looking into other applications for the upcycling method.

8 . Wildlife faces threats from habitat destruction, pollution, and some human activities. Although protecting wildlife may seem too hard at times, even small actions in your own neighborhood can help protect many different animals. Here are some tips on how to protect wildlife through small actions. Create wildlife­friendly areas in your backyard.

When trying to make your garden more beautiful, you can choose plants that can provide food and shelter for the native wildlife. This will also help cut down on pollution. Besides, bird or bat houses in your yard or garden can attract and shelter more species.

Avoid harming the natural ecosystem (生态系统) in your backyard.

Some plants from other places can kill or harm the native plants that provide food and shelter for wildlife.

Have a greener lifestyle.

By using less water and fewer fuels, you will do good to help protect the wildlife around you. Take buses or the subway if you can, turn off the electric devices when you’re not using them, take showers for a shorter time, and keep the temperature in your room at or below 68 Fahrenheit degrees in winter.

Buy products that are friendly to wildlife.

Don’t buy products that are made from endangered animals. Keep in mind that some endangered animals are killed by traps, or hunters who are eager to earn money with them.

Donate money to organizations that protect wildlife and their habitats.

You can give money to organizations or groups that protect wildlife in your neighborhood, thus promoting their work.

10 . New bio-plastics are being made in laboratories from straw, wood chips and food waste, with researchers aiming to replace oil as the source of the world’s plastic.

The new approaches include genetically modifying bacteria to eat wood and produce useful chemicals. But the bio-plastics are currently significantly more expensive to make than fossil fuel-based plastics.

Land and seas around the world, from high mountains to deep oceans, have become polluted with plastic, prompting major public concern. The world has produced 8bn tons of plastic since the 1950s and demand is still rising.

While some waste plastic is recycled, much of it is burnt to produce electricity, resulting in carbon emissions that drive climate change. In contrast to plastic made from oil, plastics made from plant-based materials only release the carbon the plants absorbed from the air as they grew. Bio-plastics will also give more options for products that biodegrade (生物降解) in the environment, although they can be made very long-lasting if required.

“Plastics are an incredible enhancement to our daily lives,” said Paul Mines, CEO of Biome Technologies in the UK, which has spent t5m in the last five years on bio-plastics research. “But we can’t go on using fossil fuel-based materials. About 6-7% of every barrel (桶) of oil is used to make plastics.”

“Using plant materials is feasible,” said professor Simon, at the University of York. “Replacing half of the nation’s plastic bottles could be done using just 3% of the sugar beet crop, 5% of wheat straw or 2.5% of food waste,” he said.

Currently, just a few thousand tons of bio-plastic are used in the UK each year, compared to millions of tons of conventional plastic. Mines said this could rise to about 20,000 tons in the next five years.