【推荐1】There was a time when a trip to the supermarket in theUnited States often ended with a seemingly simple question from the cashier: “Paper or plastic?” Well, which type of bag would you choose?

While all types of bags have some influence on the environment, it has long been supposed that paper bags are kinder. They are made from a renewable source, break down easily, burn without giving off thick smoke and can be recycled. However, the producing process behind paper bags uses more energy than that of plastic ones. How can this be true?

Studies show that paper bag production requires four times as much energy as plastic bag production. And the amount of water used to make paper bags is twenty times higher. Besides, the influence on forests is very serious. It takes about fourteen million trees to produce ten billion paper bags, which happens to be the number of bags used in the United States yearly.In terms of recycling, the idea that paper bags are more environmentally friendly than plastic ones can be quickly discarded. Research shows it requires about 98% less energy to recycle plastic than it does to recycle paper.

Even though paper bags might be more harmful than plastic ones, plastic still seems to be considered by governments as the more harmful of the two. In Ireland, for example, a tax has been introduced to discourage the use of plastic bags. People have to pay 22 cents for every plastic bag, and as a result, their use has dropped quickly.

There’s no doubt that it makes more sense to reuse these bags. However, we don’t seem to be doing that at present. Cloth bags are a better choice, but still, their production also has a bad influence on the environment. So what to do? How should I we answer the question of “Paper or plastic?” It seems that we first need to ask ourselves one more general question: “What can I do to help the environment?”

【推荐2】Rainbow -coloured rubbish is the colourful waste created by a Swedish city with a unique recycling system. Like many cities in Sweden, Eskilstuna has an impressive recycling record. It met the EU’ s 2020 target of recycling 50％ of waste many years ago. But almost everyone who lives here follows a strict recycling policy at home. People are expected to sort their household waste into seven separate categories, including food, textiles, cartons and metal. But what really makes the system stand out is the bright colour code.

The reason for this becomes clear at the city’ s recycling plant. The bags arrive all jumbled up because they’ re collected altogether, once a fortnight from outside people’ s houses. But thanks to those bright colours, scanners can select the bags and separate them efficiently. The food waste in green bags is processed on site into slurry(浆) to make biogas, which powers the city’ s buses. One of the benefits of this method of recycling is that there is less cross-pollution,so more of the recycled waste can actually be used to make new things.

Like the rest of Sweden, Eskilstuna is committed to sending zero waste from its citizens to landfill(垃圾堆) . Waste that cannot be recycled is incinerated at a local plant to generate electricity. This reduces reliance on fossil fuels, but does create greenhouse gases. As countries a-round the world try to improve their recycling rates, some may look to Eskilstuna as an example to follow— as long as they think they can persuade their citizens to get busy sorting at home.

【推荐3】CORAL reefs are,in fact,a necessary part of our ecosystem and provide opportunities for human beings to gain a better understanding of the ocean.Unfortunately,they're also disappearing faster than ever.

According to a warning by the US National Oceanic and Atmospheric Administration(NOAA) on Oct.8,the world is in its third recorded global coral bleaching（白化）since 1998 and 2010.This means no place with coral has been spared,as coral reefs are coming into contact with increasingly warm seas,which is leading to them dying off in large numbers.

Coral bleaching is like human cancer.It happens when corals are under stress from changes in light,nutrients,or temperature.This causes the coral to drive away the symbiotic algae（共生藻类）,living within their tissues（组织）, which play an important role in providing food for coral while making it colorful.Without the algae,coral reefs become pale and weak.In some cases they are not able to recover and eventually die off.

The current coral bleaching event started back in late 2014 and continued into this year with no signs of stopping.The BBC reports that 35% of coral reefs in the world will likely be affected,and an estimated 4,633 square miles (about 120,000 square kilometers) of coral reefs could die.

The loss of coral reefs is no small matter.Although they only take up 0.1% of the ocean floor,coral is home to about 25% of marine life.This isn't just a problem for divers and fish,as Eakin pointed out.Coral reefs are important globally,he added,as they protect shorelines,produce money in tourism,and help provide food for 500 million people worldwide.So people cannot overlook the environmental,economic and social effects of the loss.

The NOAA warning about coral bleaching came just about two months before a global climate summit（峰会）in Paris,where hundreds of world leaders will attempt to work our a plan to fight climate change.

Oceans will be a key subject during the summit,and Eakin says there's an "absolutely urgent need" for action.

【推荐2】Currently, vegetarianism is increasingly popular, but it is still not the best option for many. If you may be contemplating removing meat from your diet but do not want to go completely meat-free,perhaps try going meat-free for just one day a week.

Sharon Palmer, a registered dietitian and author of Plant Powered for Life, discuses how "research consistently shows that plant based diets are linked with a lower risk of obesity, hypertension,heart disease ,type 2 diabetes and cancer.

She says, "Even going meatless one day a week can make a difference, as you increase all of those whole plant-foods beans, wholegrains, nuts, seeds, vegetables,fruits-and decrease more animal foods, in particular red and processed meat. A high intake of these foods has been linked with increased disease risk.”

Deciding to have a more plant-based diet also increases your intake of fiber, vitamins healthy fats and minerals. To help to do this，stocking your fridge with a variety of beans seasonable veggies , wholegrains, herbs, nuts and seeds is Palmer's secret to eating more plant-based meals.

Palmer's other recommendation is“plantifying”"your favorite dishes. "Just make your favorite dishes or meals plant-based,with a few changes. If you love Taco Tuesday, make your tacos veggie by skipping the meat and serving black beans or a vegetarian mushroom with tofu filling. If you love Indian food, skip the chicken masala and have chickpea masala instead. These will be foods you already love and are familiar with.”

Her biggest advice is to pick one day a week to follow through this and mark it on your calendar, "I love the Meatless Monday idea because people often start their best behaviour at the beginning of the week. . .However, there may be a better day of the week for you. So just plan it. " Palmer said.

【推荐1】We’ve known for years that plants can see, hear, smell and communicate with chemicals. Now, reported New Scientist, they have been recorded making sounds when stressed.

In a yet-to-be-published study, Itzhak Khait and his team at Tel Aviv University, in Israel, found that tomato and tobacco (烟草) plants can make ultrasonic (超声的) noises. The plants “cry out” due to lack of water, or when their stems (茎) are cut. It’s just too high-pitched (音调高的) for humans to hear.

Microphones placed 10 centimeters away from the plants picked up sounds in the ultrasonic range of 20 to 100 kilohertz (千赫兹). Human hearing usually ranges from 20 hertz to 20 kilohertz. “These findings can change the way we think about the plant kingdom,” they wrote.

On average, “thirsty” tomato plants made 35 sounds an hour, while tobacco plants made 11. When plant stems were cut, tomato plants made an average of 25 sounds in the following hour, and tobacco plants 15. Unstressed plants produced fewer than one sound per hour, on average.

Perhaps most interestingly, different types of stress led to different sounds. The researchers trained a machine-learning model to separate the plants’ sounds from those of the wind, rain and other noises of the greenhouse. In most cases, it correctly identified (辨识) whether the stress was caused by dryness or a cut, based on a sound’s intensity(强度) and frequency. Water-hungry tobacco appears to make louder sounds than cut tobacco, for example. Although Khait and his colleagues only looked at tomato and tobacco plants, they think other plants also make sounds when stressed.

If farmers could hear these sounds, said the team, they could give water to the plants that need it most. As climate change causes more droughts (旱灾), they said this would be important information for farmers. “The sounds that drought-stressed plants make could be used in precision agriculture (精准农业),” said Anne Visscher at the Royal Botanic Gardens, Kew, in the UK.

Khait’s report also suggests that insects and mammals (哺乳动物) can hear the sounds up to 5 meters away and respond. For example, a moth (蛾子) may decide not to lay eggs on a water-stressed plant. Edward Farmer, at the University of Lausanne, Switzerland, is doubtful. He said that the idea of moths listening to plants is “a little too speculative”.

If plants are screaming for fear of their survival, maybe we should be glad we can’t hear them.

【推荐2】Slang(俚语) is very informal language which is often used by young people. It’s hard to keep up to date with it as new words and phrases appear and evolve (发展). Living in a multicultural society has an effect on language, especially on the young, whose friends are often from a mix of backgrounds. TV and music also have a big impact. A complete list of slang is difficult to make; by the time it was finished, the list would be out of date. However, here are a few examples:

Safe, sorted, sound, cool or wicked all mean “That’s good” or “I understand”.

Instead of using different tag questions (附加疑问句) like “… isn’t it?”, “… can’t you?” or “… don’t they?”, people use “innit”.

For example, “He can dance really well, innit!” (= He can dance really well, can’t he?) or “They always say that, innit.” (= They always say that, don’t they?)

Instead of saying “very”, “really” or “completely” use “well”, for example, “I’m well tired” or “You got it well wrong!”

“Whatever” means “I don’t care”, for example, A: “But the teacher says we can’t leave until we’ve finished.” B: “Whatever. I’m going.”

“He’s fine” or “he’s fit” both mean “He’s good-looking”. Fine and fit can describe a boy or a girl.

Not everybody uses slang and not everybody likes it. A school in the north of England recently told its pupils to stop using slang words such as “hiya” (hello), “cheers” and “ta” (both mean “thank you”) if they wanted to get a place at university or a good job.

When British people use language like this, it’s no surprise that some say they can’t understand native speakers. But perhaps learners don’t need to worry so much. Research shows that most of the English spoken around the world today is between non-native speakers of the language.

So, how important is it to understand these slang words and expressions? If you watch films or TV in English, read magazines in English, chat online in English or are interested in English song lyrics, then understanding slang can be very useful. You probably won’t see much slang in your English examination, though.

【推荐3】The practice of students endlessly copying letters and sentences from a blackboard is a thing of the past. With the coming of new technologies like computers and smartphone, writing by hand has become something of nostalgic (怀旧的）skill. However，while today’s educators are using more and more technology in their teaching, many believe basic handwriting skills are still necessary for students to be successful---both in school and in life.

Virginia Berninger, professor of educational psychology at the University of Washington, says it’s important to continue teaching handwriting and help children acquire the skill of writing by hand.

Berninger and her colleagues conducted a study that looked at the ability of students to complete various writing tasks---both on a computer and by hand. The study, published in 2009, found that when writing with a pen and paper, participants wrote longer essays and more complete sentences and had a faster word production rate.

In a more recent study, Berninger looked at what role spelling plays in a student’s writing skills and found that how well children spell is tied to know well they can write. “Spelling makes some of the thinking parts of the brain active which helps us access our vocabulary, word meaning and concepts. It is allowing our written language to connect with ideas.” Berninger said.

Spelling helps students translate ideas into words in their mind first and then to transcribe(转换）“those words in the mind written symbols on paper or keyboard and screen,” the study said. Seeing the words in the “mind’s eye” helps children not only to turn their ideas into words, says Berninger, but also to spot spelling mistakes when they write the words down and to correct then over time.

“In our computer age, some people believe that we don’t have to teach spelling because we have spell checks,” she said. “But until a child functional spelling ability of about a fifth grade level, they won't have knowledge to choose the correct spelling among the options given by the computer.”

【推荐1】Wealthy people may be likely to be against redistribution of wealth, according to new research. The findings indicate that it is because people use their own neighborhoods and communities as a standard of how much wealth other people have, leading wealthy people to believe the bigger population as being wealthier than it actually is.

“If you're rich, there's good chance for you to know lots of other rich people and relatively few poor people； likewise, if you're poor, you're likely to know fewer wealthy people and more poor ones," says study co-author Robbie Sutton. "Even if people think objectively and follow rules of statistical inference, richer and poorer people may be led by the information available to them, to very different conclusions about how wealthy other people are, on. average, and how wealth is distributed across society. ”

"These results suggest that the rich and poor do not simply have different attitudes to how wealth should be distributed across society； rather, they subjectively experience living in different societies," adds Rael Dawtry, the study's lead author. "In the relatively richer America crowded by wealthier Americans, there is perhaps less need to distribute wealth more equally. " The findings suggest that attitudes toward wealth distribution come from more than just an economic motivation to protect one's self-interest or financially protective political ideologies （意识形态）----the information provided by our living environment also plays an important role.

The research covered over 600 US adults to complete an online survey in two studies. The participants were asked to estimate the distribution of household income for their social contacts and also for the whole US population in two studies—they estimated what percentage of people fell into each one of 11 income groups； then they estimated the average income of people within each income group. Then, the participants were asked how fair they thought income distribution in the US was and how satisfied they were with it. The participants also answered questions testing their attitudes toward redistribution.

To ensure that the findings were actually related to the individual s social circles and not some other psychological bias, the researchers then analyzed data from over 4,000 voters in New Zealand. The data showed that the relationship between voters' income and their perceptions of economic fairness in New Zealand was driven by the level of economic condition in their neighborhood.

"These results show the importance of examining ecological processes, in addition to political ideological or self-interest, for understanding economic preferences, says Dawtry. "Attitudes to redistribution and the economic position appear to be subject to informational biases in the environment as well as biases in the mind. " According to Sutton, the findings may also help to explain the political polarization （两极分化）observed in countries like the United States.

"As richer and poorer people increasingly live separated live, the information available becomes increasingly misunderstood, and increasingly different, he notes. "People are, effectively, living in an informational bubble, surrounded by people with incomes like theirs but unlike many other Americans."

【推荐2】Not long ago, Egypt marked the 150th anniversary of the opening of the Suez Canal. The canal connects the Mediterranean Sea to the Red Sea and the Indian Ocean. It helped speed world trade between the East and the West. But the man-made waterway has also helped speed the rise of other things, such as invasive(入侵的)non-native species (物种). Scientists say the invasive creatures have damaged the Mediterranean’s environment and caused native species to disappear.

The number of non-native creatures has risen since the Suez Canal was widened in 2015. The “New Suez Canal” has raised concerns in Europe and brought disagreement from many Mediterranean countries. Bella Galil is an Israeli biologist who has studied the Mediterranean for over 30 years. She says much of the ecological(生态的)damage cannot be repaired. She said urgent action is needed to ease the effects of the invasive fish and other sea life.

Galil works at Tel Aviv University’s Steinhardt Museum of Natural History. She noted that the widening and deepening of the Suez Canal has created a “moving aquarium” of species. These creatures could make coastal waters almost unusable for human beings. Galil believes the number of invasive species has reached 400. That is twice the number 30 years ago. She said this is a “historic example of the dangers of unintended consequences.”

Israel is now dealing with huge numbers of poisonous(有毒的) jellyfish that affect coastal power centers and keep people from visiting the seashore. Other poisonous species, such as the lionfish and silver-cheeked toadfish, are also appearing.

Galil said the problems of invasive species can be compared to those of climate change, pollution and over-fishing. She argues that the new species have caused a major “restructuring” of the environment. This has endangered native species.

Some experts have suggested that increasing salt levels in the canal itself could create a barrier(障碍物) that would keep invasive species out.

【推荐3】News anchors(主播) must have been reluctant to read out the following news: Xin Xiaomeng began working as the world’s first female artificial(人工的) intelligence news anchor at Xinhua News Agency on Sunday, three months after a male robot joined the profession.

Unlike previous news robots though, Xin does not read news like a cold machine; she reads it almost like a human being. The muscles on her face stretch and relax — and her reactions change as she continues reading. That’s why many news anchors were worried: Will AI replace us in the near future?

To find the answer, we have to analyze the technologies that support Xin at her job. Three key technologies are used to support Xin. First, samples of human voices are collected and synthesized (合成). This is followed by the collection and synthesis of human muscle movement samples. And third the voices and movements are married in a way that when the AI news anchor reads, the micro- electric motors behind her face move to make her expressions seem more human.

Yet we need a thorough knowledge of deep learning technology to make a robot imitate a person’s voice. The developer needs to collect tens of thousands of pieces of pronunciations, input them into the machine and match them with the text for the AI to learn and read. The process for imitating facial movements is similar. The developer has to analyze the movements of the 53 muscles in the human face, make a model set from the collected data for the AI news anchor to learn, and imitate the movements of facial muscles via programs

Both the technologies used to make Xin’s performance impressive are mature. The real difficulty lies in the third — the technology to match the pronunciations with facial movements so that Xin’s expressions vary according to the content of the news report. In fact, Xin’s expressions don’t always change according to the content. As a result, her expressions look anything but human. Actually, AI is still no match for human qualities.