【推荐1】Traditionally, the more people in a city, the fewer trees there are. To create space for houses, offices and other buildings, nature takes second place. But, if the architect Stefano Boeri has anything to do with it, this will soon be changing.

Boeri has designed a forest city, to be created in the north of Liuzhou in   Guangxi region in southern China. This mountainous area was chosen to be “a city where living nature is totally intertwined with architecture.” According to Boeri, instead of completely getting rid of the trees to build houses, the city’s design considers the surrounding greenery. Homes and commercial buildings will be covered with trees, with gardens on the balconies (阳台) of every floor, and rooftops that are home to miniature forests.

“I have been working on the idea of urban forestation for years,” says Boeri. “In those areas of the planet where it is still necessary to build new cities, we are planning real forest cities for a maximum of 150,000 citizens.”

The Liuzhou Forest City will be connected to central Liuzhou via a railway line and a road. It will be home to 30,000 people, and include commercial and recreational spaces, two schools and a hospital. On top of this, the vegetation will absorb carbon dioxide and pollutants, as well as releasing oxygen into the atmosphere.

Development is well underway for the forest city. “Our masterpiece for a forest city in Liuzhou has been approved by the local government,” says Boeri. Now, the government is starting the process of selling land to interested developers. “The current phase is still ongoing for land selling,” says Boeri. Building is expected to begin in 2020. At the same time, the firm has copied the concept in Lishui, a city in the southeast of China. The masterpiece has also been given the thumbs-up by local governments here, and the developer is collecting funds to launch the project.

If the Chinese cities prove successful, Boeri hopes that the idea will take hold across the world. “We are developing the same concept in other places with different climate conditions, such as Mexico and north Africa,” he says.

And there is science behind the idea of planting trees to halt climate change. A study earlier this year by scientists at ETH Zurich found that planting at least a trillion trees around the world could lock up 205 billion tonnes of carbon, once the trees are mature, helping to offset the effects of releasing greenhouse gases into the atmosphere.

【推荐2】Are you afraid of sharks? What about snakes or spiders? Put those fears aside: because in the U.S. you’re far more likely to be killed or injured by a deer skipping across the road.

Deer cause more than 200 humans deaths each year, plus some 29,000 injuries, all because of 1.2 million collisions between vehicles and deer. Most incidents occur in the eastern U.S., where deer prosper without natural predators like wolves and mountain lions.

“That’s the region in the U.S. where deer-vehicle collisions are such a problem, and where it seems like an effective large carnivore reintroduction could make a really big difference.” says wildlife biologist Laura Prugh from University of Washington. She thinks it would help to reintroduce predators like mountain lions, also known as cougars, pumas or panthers, to parts of their historic range from which they’ve been driven out.

The researchers say that bringing the predators back to the eastern U.S. would mean 22 percent fewer collisions between cars and deer over three decades. Each year would see five fewer human deaths, 680 fewer injuries and a savings of some 550 million. Sophie L. Gilbert thinks there are great socioeconomic benefits of large predator restoration through reduced wildlife-vehicle collisions and she says, says, “Cougars have shown that they can coexist in short distance with people, with very few conflicts, in a lot of areas out west.”

Still, some folks might be understandably nervous about this kind of plan. After all, reintroducing predators doesn’t come without risks to pets and to livestock, and very occasionally to people.

“Our fear of large predators is so natural and intense that I don’t think it’s possible to just completely clear it with statistics... What I hope is that knowing that there actually can be some measurable benefits might make people a little more supportive and maybe balance that fear a little bit.” says Laura.

Indeed, the statistics show that cougars would prevent five times as many human deaths from deer-related accidents as they would cause by attacks. But it’ll be a tough sell: the press will cover cougar attacks, but a statistically prevented death does not make the news. Nevertheless, “If people in the west can put up with having mountain lions around, I would hope that New Yorkers would be up for the challenge as well.”

【推荐3】Many people wrongly think that cities don’t have farms and that fruits and vegetables are only grown in the country. Believe it or not, there are more and more urban farms popping up in cities all over the world.

Alexandra Sullivan, a food system researcher in New York City, studies urban agriculture. Urban agriculture is another name for farming and gardening in a city environment. Ms. Sullivan studies everything from tiny gardens in empty lots between buildings to bigger fields that have been planted and grown. According to Ms. Sullivan, “Urban agriculture has existed since cities have, across the world.”

The number of humans living in urban areas, or cities, is increasing. The amount of people who want to garden in urban areas is also rising, Ms. Sullivan says, “In small gardens, on rooftops and indoors, they grow fruits, vegetables, grains, and herbs, and raise animals to produce milk, eggs, honey, and meat. They use these foods as supplements to food produced by rural agriculture.” Even though some people who live in urban areas grow crops, urban residents still need to rely on food grown in rural areas. This is because a city doesn’t have enough space to grow enough food for everyone living in it.

In New York City, urban farmers have come up with many different ways to grow their own produce, even though there isn’t a lot of room. For example, Brooklyn Grange is a farming operation that has two rooftop vegetable farms in New York City. All together, the farms are made up of 2.5 acres of rooftop space. This makes Brooklyn Grange one of the largest rooftop farming operations in the world.

Brooklyn Grange grows all kinds of things. The farming company sells its vegetables to local residents and restaurants. And because the farms are on rooftops, they are specially adapted to their urban location. They use available space that is not needed for anything else. As more urban farmers find ways to grow food in cities, urban residents will be better able to get fresher materials for their meals.

【推荐1】Masks that helped save lives are proving a deadly danger for wildlife, with birds and sea creatures trapped in the shocking number of thrown-away facial coverings. Single-use masks have been found around pavements, waterways and beaches worldwide. Worn once, the thin protective materials can take hundreds of years to decompose. “Face masks aren't going away any time soon—but when we throw them away, these items can harm the environment and the animals,” Ashley Fruno of animal rights group PETA said.

In Britain, a gull was rescued by the RSPCA after its legs became tangled in the straps of a mask for up to a week. The animal welfare charity took it to a wildlife hospital for treatment before its release.

The biggest impact may be in the water. More than 1.5 billion masks made their way into the world's oceans last year, accounting for around 6,200 extra tonnes of ocean plastic pollution, according to environmental group Oceans Asia.

Conservationists in Brazil found one mask inside the stomach of a penguin after its body was washed up on a beach, while a dead pufferfish was discovered caught inside another off the coast of Miami. French campaigners found a dead crab trapped in a mask near the Mediterranean. Masks and gloves are “particularly problematic” for sea creatures, says George Leonard, chief scientist from NGO Ocean Conservancy. “When those plastics break down in the environment, they then enter the food chain and impact entire ecosystems.” he added.

There has been a shift towards greater use of reusable cloth masks as the pandemic has worn on, but many are still using the lighter single-use varieties. Campaigners have urged people to bin them properly and cut the straps to reduce the risk of animals becoming trapped. Oceans Asia has also called on governments to increase fines for littering and encourage the use of washable masks.

【推荐3】Satellites are an important part of our ordinary lives. For example, the information for weather forecasts is sent by satellite. Some satellites have cameras which take photographs of the Earth to show how clouds are moving. Satellites are also used to connect our international phone calls.

Computer connections of the World Wide Web and Internet also use satellites. Many of our TV programmes come to us through satellite. Airplane pilots sometimes also use a satellite to help them find their exact location.

We use satellites to send television pictures from one part of the world to another. They are usually 35,880 kilometres above the equator (赤道). Sometimes we can see a satellite in the sky and it seems to stay in the same place. This is because it is moving around the world at 11,000 kilometres an hour — exactly the same speed that the earth rotates (转动). A satellite must orbit the Earth with its antennae (天线) facing the earth. Sometimes, it moves away from its orbit, so there are little rockets on it which are used to put the satellite back in the right position. This usually happens about every five or six days.

Space is not empty! Every week, more and more satellites are sent into space to orbit the Earth. A satellite usually works for about 10-12 years. Satellites which are broken are sometimes repaired by astronauts or sometimes brought back to the Earth to be repaired. Often, very old or broken satellites are left in space to orbit the Earth for a very long time. This is very serious because some satellites use nuclear power and they can crash into each other.