【推荐2】Do you like the woolly mammoths (毛猛犸象) from the movie Ice Age? Too bad they’re extinct? Thanks to recent developments in biotechnology, the stuff of science fiction may soon become a reality through an attractive process called “de-extinction”, which aims to bring the extinct species back. The resurrected (复活的) species are functionally equal to the original extinct species, but they are not exact copies.

There are three primary techniques of de-extinction. One of them is that scientists deliberately select existing species with similar characters to the extinct species to produce later generation. This is a natural method. Another is cloning. A cloned animal is created by obtaining the DNA of the extinct animal. The later generation will be an identical copy of the extinct species. This is only applied to animals that are either endangered or have recently gone extinct, as it requires well-preserved eggs. The third is the newest technique, genetic engineering (基因工程). It uses gene-editing tools to place selected genes from extinct animals in place of those present in its closest living relative.

If we refer to Jurassic Park, resurrecting extinct animals is a terrible idea. Thankfully, we don’t have to worry about dinosaurs running wildly, as their DNA has disintegrated over the 65 million years since their extinction. DNA can survive for several million years at best under certain rare conditions, but does that mean we should do that?

De-extinction is more for ecology than for tourism. Ecologist Ben Novak said, “All animals perform critical roles in their ecosystem. Woolly mammoths, for example, were excellent gardeners. Their disappearance was followed by a loss in diversity and the Arctic grassland became a cold, ice field. If a resurrected animal is always going to be a zoo animal then it shouldn’t be brought back.”

【推荐3】Owning a pet is a fun and rewarding experience.    1    . So how can you make sure that you choose the right one for you? Here are some top tips.

Do your research

You may like the look of a particular pet but that doesn’t mean it is right for you. Every pet has its own personality and certain breeds (品种) of animals often have strong traits, so think carefully about what you want from your pet and do some research before you take one on.

    2    . For example, French bulldogs and pugs can suffer a number of health issues over their lifetime, including problems with their breathing and skin conditions due to their exaggerated features. We’d urge owners to really do their research before taking on one of these breeds.

    3    .

For example, if you work full time and you want a dog, who would take care of it during the day? If you want a cat, will it have access to outside space while you’re out during the day? Do some research on the size, temperament and exercise requirements of different pets to make sure they’re the right choice for you.

Do your sums

From everyday things like insurance, food and toys to unexpected vet bills, having a pet is certainly a financial commitment.    4    .

Use a reputable breeder

Want to buy a pedigree (纯种的) dog or cat?    5    . Ask the breeder for all the relevant paperwork and see the pet’s parents to observe their temperament, general health and welfare. Don’t purchase one online or from dealers who offer multiple breeds or types of pets, or you will be cheated.

【推荐1】Compared with the other environmental issues, littering often takes a backseat — but it’s more pressing than we may think.

If you were to throw, for example, a banana peel out of your car while driving along the road, that would be a completely harmless action, because it’s part of a fruit — right? Actually, no. A banana peel can take up to two years to break down, and with a third of drivers admitting to littering while driving, that’s a whole lot of banana peel garbage mountain. An orange peel and a cigarette end have a similar biodegrading (降解) term to that of a banana, but tin and aluminium cans last up to 100 years; and plastic bottles last forever, as do glass bottles.

In spite of the fact that longer-lasting materials will serve to damage (破坏) the environment and its animals for longer, we can’t measure the harm of a certain type of rubbish only by its lifetime. For example, even with a fairly short biodegrading time, more than 120 tons of cigarette-related litter can be found in the UK every day. Similarly, our regular littering here and there has caused the UK s mouse population to increase by 60 million.

It’s not a cheap habit either: UK pays £500 million to keep our streets clean, and when you include our green spaces, that goes up to £1 billion. So, it’s not surprising that if caught fly-tipping (倾倒垃圾) you could face a £20,000 fine or even jail time. In spite of how heavy these punishments might seem, however, among the reported cases only 2,000 were convicted (定罪) out of 825,000, so we still have some way to go.

【推荐2】China and India are leaders in improving global(全球的) tree cover, a new study based on NASA research showed.

They took a 31.8% part together of the total global new leaf area between 2000 and 2017. China played a major role, adding 25% to this increase, and India added 6.8%, followed by Canada and Russia. The study in the Nature Sustainability journal shows that more than 5.5 million square kilometers of green leaf area was added globally. Since 2000, there has been a five-percent increase in global green cover, it said.

“The greening over the last twenty years shows an increase in leaf area on plants and trees which is as large as the area of the entire Amazon rainforest," Chi Chen, a Boston University researcher and lead of the study told Nature Sustainability. Large plantation activities to protect forests in China contributed nearly 42% to the country's green cover, and agriculture added another 32%. In India, 82% of the increase in leaf area was because of agriculture.

“China and India take up one-third of the greening, but hold only nine percent of the planet's land area covered in green plants," Chi Chen told NASA Earth Observatory. “That is a surprising finding, considering the land degradation(退化) in countries with large populations.”

Boston University's research team first detected an increase in global green cover in the 1990s but were unsure about what contributed to the increase. Finally, with the help of NASA's Terra and Aqua satellites research, they managed to find out the increase in leaf cover from different areas and places.

【推荐3】In Singapore, buses have been given the green light to find new ways to reduce emissions (排放) and improve the air quality of their services.

Last month, GWS Living Art, a company specializing in urban green structures installed (安装) green roofs on 10 public buses. While a bus might not seem like the typical location for a green roof, the installation could provide environmental and economic benefits. According to research by Michigan State University, green roofs are great at reducing polluting emissions, providing spaces for nature and cooling cities through the water that evaporates (蒸发) from their leaves and by shading surfaces that would otherwise absorb heat.

“While the impact of green plants on buildings has been well documented, much less is known about the effects of them on moving vehicles,” said Tan Chun Liang, a research fellow at National University of Singapore who advises the “Garden on the Move” bus campaign. This bus campaign is part of a three-month study to test whether green plants can help lower the temperature inside the buses and reduce the amount of fuel needed to power the air-conditioning. Liang hopes the research will provide a possible solution for cities to fight against global warming and the Urban Heat Island (UHI) effect -- when a city experiences much warmer temperatures than nearby rural areas, due to the heat produced and absorbed by industry, traffic and building materials.

To make Singapore a “Garden City,” the government has joint this bus campaign with other green projects such as the Green Mark Scheme which aims for 80% of building to be green by 2030 and Gardens by the Bay, an eco-friendly garden featuring solar-powered “supertrees” and over 1.5 million plants.

【推荐2】My favourite book is The Adventure of Tom Sauyer by Mark Twain. Tom lives with his aunt Polly in a quiet street of St. Petersburg, Missouri. He’s a lively and clever young boy, and he finds himself in many exciting adventures. He runs away with his two friends, Huck Finn and Joe, to an island in the middle of the Mississippi River for several days. With Huck he goes looking for treasure, with Becky he gets lost in a cave. And finally, they find a box of gold.

My favourite scene in the book is when everyone thinks Tom is dead. He decides to go to his own funeral(葬礼). He hides and watches for a time and then suddenly he appears. Everyone is surprised to see him but they’re also pleased to see him alive.

Tom is the hero of the story, but there are other important characters. Huck is an outsider and everyone is afraid of him. Becky is pretty with fair hair, Joe is Tom’s best friend. And Injun Joe is the bad man of the story.

The theme of the story is about children growing up. It describes how strangers are seen in small towns of America. Finally, it talks about freedom, social rules and how people are punished for bad behaviour.

Why do I think The Adventure of Tom Sawyer is a great book? Mark Twain wrote the story in 1876, but it’s still read and loved by people all over the world today. And although it’s only a story, Twain wrote it in the everyday English of the southern states of America in the 19th century, so it sounds very real. Today its thought to be one of the greatest books in American literature. Go on-read it! I know you’ll enjoy it, too.