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.

4 . Tips for Green Travel with Kids

Travelling doesn’t mean letting go of all the eco-friendly choices we work so hard to achieve in our daily life. Here are a few tips for green travel with kids.

Booking nonstop flights whenever possible will reduce carbon emissions (碳排放). If the closest local airport doesn’t have nonstop flights to a certain place, check with other local airports to see if nonstop flights are available.     1    

It’s easy when travelling to pull in to fast food restaurants for snacks.     2     My kids love to help plan snacks. I let them create their own snacks for the trip at home.

    3     At the airport, keep your reusable bottles empty until you have passed through the security (机场安检区). Fill them up on the other side of the security checkpoint. Single-use plastic water bottles create unnecessary waste and the plastic can be harmful to your health.

    4     In addition, opening a few windows and turning off the air conditioner (空调) are also good ways to save energy. You should also help your children keep their good, green habits while travelling. Sometimes vacation can mean more than one shower each day-once in the morning and again after getting out of the pool. Pay attention to the number of showers (淋浴) and the length of showers.     5    

5 . The last complete ice shelf in the Canadian Arctic has collapsed (倒塌). The Milne Ice Shelf is _______ Ellesmere Island, Canada. The shelf lost _______ 40 percent of its area in just two days at the end of July, 2020. 

Above normal air temperatures, offshore winds and open water in front of the shelf are all parts of the _______ for its break-up.The shelf area shrank (缩小) by about 80 square kilometers. By comparison, the island of Manhattan in New York _______ about 60 square kilometers.Temperatures in the polar area have been _______ intense (强烈的). Summer in the Canadian Arctic in 2020 has been 5 degrees Celsius _______ the 30-year average. That has _______ smaller ice caps, _______ can melt quickly. As a glacier disappears, more bedrock is left _______. This then speeds up the melting ________. A research camp, including instruments for measuring water flow through the ice shelf, was lost when the shelf at Ellesmere Island collapsed. 

“It was only a ________ of time,” said Mark Serreze, director of the National Snow and Ice Data Center. His study showed the ice caps were ________ to disappear within five years. Their disappearance was ________ last year, when NASA satellite images of the area showed a complete lack of snow and ice. Serreze’s ________ trip to the Arctic was many years ago. “When I was there in the 1980s, I knew every square inch of those ice caps,” Serreze said. “You have the good ________. It’s like your first girlfriend. I want her back.”

6 . China is showing the world its great resolve in the global climate campaign with concrete and self­motivated efforts as well as serious commitment.

At the opening ceremony of the Paris climate summit, Chinese President Xi Jinping restated China’s plan made in June to cut its carbon emissions( 排放)per unit of GDP by 60­65 percent from 2005 levels by 2030, and increase non­fossil fuel sources in primary energy consumption to about 20 percent.

With a large population, China is facing increasing resource limits, severe environmental pollution and a worsening ecosystem, and its citizens are also becoming increasingly aware of environmental problems. Suffering environmental problems and seeing the efforts as important to transforming its economic growth pattern, the country has much at risk if climate change is left unattended.

Actually, climate change efforts are already included in China’s medium­and long­term program of economic and social development, and ecological efforts are the clear characteristics in China’s 13th Five­Year Plan(2016­2020)．

Although it is and will be a developing country for a long time to come, China has been actively involved in the global campaign against climate change, now topping the world in terms of energy conservation and use of new and renewable energies.

However, China’s development rights need to be respected. It is unfair to overstress China’s status as one of the world’s largest greenhouse gas emitters and regard it as the major part of responsibilities in the global fight against climate change.

It is worthy of notice that China’s emissions of greenhouse gases per person are far lower than those of developed countries, especially the United States, although rapid economic expansion and its population base have made it one of the biggest producers of the gases.

To show its great resolve, Beijing in September also announced the establishment of an independent South­South cooperation fund of ￥20 billion to help developing countries affected by global warming.

While China is eagerly accomplishing its policy commitments, developed countries should stop questioning China’s commitment to fighting climate change and pointing fingers, and start shouldering their due responsibilities instead.

9 . As a result of pollution, Lake Erie, on the borders of the USA and Canada, is now without any living things.

Pollution in water is not simply a matter of “poisons” killing large numbers of fish overnight. Very often the effects of pollution are not noticed for many months or years because the first organisms (生物体) to be affected are either plants or plankton. But these organisms are the food of fish and birds and other creatures. When this food disappears, the fish and birds die too. In this way a whole food chain can be wiped out, and it’s not until dead fish and water birds are seen at the river’s edge or on the seashore that people realize what is happening.

Where do the substances which pollute the water come from? There are two main sources—sewage (污水) and industrial waste. As more detergent (洗涤剂) is used in the home, so more of it is finally put into our rivers, lakes and seas. Detergents harm water birds, dissolving the natural substances which keep their feathers water­proof. Sewage itself, if not properly treated, makes the water dirty and prevents all forms of life in rivers and the sea from receiving the oxygen they need. Industrial waste is even more harmful as there are many highly poisonous things in it, such as copper and lead (铅).

So, if we want to stop this pollution, the answer is simple: sewage and industrial waste must be made clear before flowing into the water. It may already be too late to save some rivers and lakes, but others can still be saved if the correct action is taken at once.