【推荐2】During the period from 1660 through 1800, Great Britain became the world’s leader. Language itself became submitted to rules during this period. This need to fix the English language is best illustrated in the making of The Dictionary of the English Language by Samuel Johnson. Guides to the English language had been in existence before Johnson began his project in 1746. These, however, were often little more than lists of hard words. When definitions of common words were supplied, they were often unhelpful. For example, a “horse” was defined in an early dictionary as “a beast well known”.

Johnson changed all that, but the task was not an easy one. Renting a house at 17 Gough Square, Johnson began working in the worst of conditions. Supported only by his publisher, Johnson worked on the Dictionary with five assistants. Compared to the French Academy’s dictionary, which took forty workers fifty-five years to complete (1639 — 1694), Johnson’s dictionary was completed by very few people very quickly.

Balanced on a chair with only three legs, Johnson sat against a wall in a room filled with books. Johnson would read widely from these books, mark passages illustrating the use of a particular word, and give the books to his assistants so that they could copy the passages on slips of paper. These slips were then stuck to eighty large notebooks under the key words that Johnson had selected. Fixing the word by this method, Johnson could record a word’s usage and its definition.

How many passages were used? According to Johnson’s modern biographer Walter Jackson Bate, the original total number could have been over 240, 000. How many words were defined by the lexicographer? Over 40, 000 words appeared in two large books in April of 1755. Did Johnson fully understand the huge task he was undertaking when he began? As he told his contemporary biographer James Boswell, “I knew very well what I was undertaking and very well how to do it — and have done it very well.

【推荐3】Once a New Zealand teacher asked where I live. “In the white building,” I answered.

“At our university both girls and boys live in the same dormitory.” I added.

Beyond my expectation (出乎意料), however, my attempt (努力) to show I am speaking American English(AE) turned out to be something else. The New Zealander seemed very puzzled (迷惑) at my answer.

With a half smile, she asked, “Really？Do they live in the same room?”

“Oh, no. They live in different rooms but in the same building.” I reacted (反应) quickly.

Later I got to know the word “dormitory”. In AE it means one building, whereas (而，却) it means one room in British English (BE).

The New Zealander misunderstood me because she spoke New Zealander English (NE), which, as we know, is much related to BE.

Nowadays, not a few English learners, who try to catch up with the fashion (时髦), choose to speak AE.

Yet, the problem is that they cannot speak pure AE, but half AE and half BE instead.

I think it necessary to keep one style in order to avoid (避免) misunderstanding.

【推荐1】According to new studies, many birds in the Amazon rainforest have become smaller as temperatures have increased. The difference hasn’t been obvious, but it has been significant enough that some scientists have suggested it’s a universal response to climate change.

But new research finds that the body size reductions aren’t happening across the board with some large­brained birds having much less significant changes.

For the study, researchers studied some data on about 70,000 birds that had died when they crashed into buildings in Chicago from 1978 to 2016. They added data on brain volume and lifespan (寿命) for 49 of the 52 species of migratory birds (候鸟) in the original study.

They found that birds with very large brains had reductions in overall body size that were about one­third of the reductions noted in birds with smaller brains. They thought that in birds, the species with big brains are the ones that build tools, manage to survive in tough environments, live longer, invest more time and energy into raising babies, and end up surviving better in the wild.

Researchers aren’t certain exactly how warmer temperatures might lead to decreasing body size in birds, but they are considering two possible explanations, which could even be happening at the same time. First, natural selection might be favoring birds that can dissipate heat better. This is because smaller birds have higher ratios (比例) of surface area to volume, so being small can help birds stay cool. Second, warmer summers might have less food available for birds at the time when they are feeding their babies. In that case, birds might be getting smaller because of decreased food over the years.

The findings don’t suggest that climate change is having zero impact on bigger­brained birds, but researchers believe these findings can inform us of climate change and help set conservation priorities.

【推荐2】The idea of being able to walk on water has long interested humans greatly. Sadly, biological facts prevent us ever accomplishing such a thing without artificial aid---we simply weigh too much, and all our mass pushes down through our relatively small feet, resulting in a lot of pressure that makes us sink.

However, several types of animals can walk on water. One of the most interesting is the common basilisk Basilicus basilicus, a lizard (蜥蜴)native to Central and South America. It can run across water for a distance of several meters, avoiding getting wet by rapidly hitting the water’s surface with its feet. The lizard will take as many as 20 steps per second to keep moving forward. For humans to do this, we，d need huge feet that we could bring up to our ears in order to create adequate w hitting. ’’

But fortunately there is an alternative : cornflour. By adding enough of this common thickening agent to water (and it does take a lot), you can create a “non-Newtonian” liquid that doesn’t behave like normal water. Now, if the surface of the water is hit hard enough, particles(粒子）in the water group together for a moment to make the surface hard. Move quickly enough and put enough force into each step, and you really can walk across the surface of an adequately thick Liquid of cornflour.

Fun though all this may sound, it’s still rather messy and better read about in theory than carried out in practice. If you must do it, then keep the water wings handy in case you start to sink--and take a shower afterward!

【推荐3】A new study has found that smiling at London bus drivers increases happiness. However, on the Number 24 bus to Hampstead Heath, Londoners are sceptical. “Bus drivers,” says Liz Hands, a passenger, “are generally annoying.”

It might seem improbable that a report on London’s buses could change behaviour. But it has happened before. London’s buses have an underappreciated role in the history of medical science. In the 1940s, a single study of London’s transport workers transformed epidemiology (流行病学), medicine and the way we live now. Every time you go on a run, check your step-count, or take the stairs instead of the lift, you are following a path pioneered by the feet of the workers on London’s buses.

In the late 1940s, doctors were worried. Britain, like many rich countries, was suffering from an “epidemic” of heart disease and no one knew why. Various hypotheses, such as stress, were suggested; but one thing that was not exercising researchers was exercise. The idea that health and exercise were linked “wasn’t the accepted fact that we know today”, says Nick Wareham, a professor of epidemiology at Cambridge University. Some even felt that “too much physical activity was a bad thing for your health”. Miners and farmers who did physical exercise also suffered from various diseases and died young.

At this time a young doctor called Jerry Morris started to suspect that the increasing deaths from heart disease might be linked to occupation. He began studying the medical records of 31,000 London transport workers. His findings were breathtaking: conductors, who spent their time running up and down stairs, had an approximately 30% lower possibility of disease than drivers, who sat down all day. Exercise was keeping people alive.

Morris’s research was eventually published in 1953, just three years after a study by Richard Doll proving the link between smoking and lung cancer. Morris’s work had consequences both big and small. Morris now also took up exercise, handing his jacket to his daughter and just running. “People thought I was bananas.” Slowly, the rest of the world took off its jacket and followed.

【推荐1】Most of the flowers in nature are red, orange and yellow. If we have seen a black flower, it’s a chance in million. People have made a census (普查) to colors of more than four thousand kinds of flowers and discovered that only eight of them are black. As we know, sunlight is formed by seven different colored lights. The wave length of each light is different, so the quantity of heat in each light is also different. Flowers, especially their petals (花瓣), are easy to be harmed by high temperature. Black flowers can take in all the light waves which cause the flowers to dry up in a high temperature. So black flowers can rarely survive sunlight. But red flowers, orange flowers and yellow flowers can protect themselves from sunlight by reflecting the red light, orange light and yellow light, each of which has a large quantity of heat.

【推荐2】Leonardo da Vinci was one of the great creative minds of the Italian Renaissance(文艺复兴), not only hugely influential as an artist and sculptor but also immensely talented as an engineer, scientist and inventor.

Da Vinci was born on 15 April 1452 near the Tuscan town of Vinci. He was apprenticed(便当学徒) to the sculptor and painter Andrea del Verrocchio in Florence and in 1478 became an independent master. In about 1483, he moved to Milan to work for the ruling Sforza family as an engineer, sculptor, painter and architect. From 1495 to 1497 he produced a mural of The Last Supper in the refectory of the Monastery of Santa Maria delle Grazie, Milan.

Da Vinci was in Milan until the city was invaded by the French in 1499 and the Sforza family was forced to flee. He may have visited Venice before returning to Florence. During his time in Florence, he painted several portraits, but the only one that survived was the famous Mona Lisa (1503-1506).

In 1506, Da Vinci returned to Milan, remaining there until 1513. This was followed by three years based in Rome. In 1517, at the invitation of the French king Francis I, Leonardo moved to the Chateau of Cloux, near Amboise in France, where he died on 2 May 1519.

The fame of Da Vinci’s surviving paintings has meant that he has been regarded primarily as an artist, but the thousands of surviving pages of his notebooks show the most brilliant of minds. He wrote and drew on subjects including geology, anatomy (which he studied in order to paint the human form more accurately), flight, gravity and optics, often moving from subject to subject on a single page, and writing in left-handed mirror script. He “invented” the bicycle, airplane, helicopter, and parachute some 500 years ahead of their time.

If all this work had been published in a form easy to understand, Da Vinci’s place as a pioneering scientist would have been beyond dispute. Yet his true genius was not as a scientist or an artist, but as a combination of the two – an ‘artist-engineer.’ His painting was scientific, based on a deep understanding of the workings of the human body and the physics of light and shade. His science was expressed through art, and his drawings and diagrams show what he meant and how he understood the way the world works.

【推荐3】Space is becoming more crowded. Quite a few low-Earth-orbit (LEO) satellites have been launched into the sky, which are designed to move around the Earth only a few hundred kilometres above its surface. SpaceX and OneWeb plan to launch LEO satellites in their thousands, not hundreds, to double the total number of satellites in orbit by 2027.

That promises to change things on Earth. LEO satellites can bring Internet connectivity to places where it is still unavailable. This will also be a source of new demand for the space economy. Morgan Stanley, a bank, projects that the space industry will grow from $350 billion in 2016 to more than $1.1 trillion by 2040. New Internet satellites will account for half this increase.

For that to happen, however, three worries must be overcome. Debris (碎片) is the most familiar concern. As long ago as 1978, Donald Kessler, a scientist at NASA, proposed a scenario (设想) in which, when enough satellites were packed into low-Earth orbits, any collision could cause a chain reaction which would eventually destroy all spacecraft in its orbital plane. Solutions exist. One solution is to grab the satellites with problems and pull them down into the Earth’s atmosphere. Another is to monitor space more closely for debris. But technology is only part of the answer. Rules are needed to deal with old satellites safely from low-Earth orbits.

Cyber-security is a second, long-standing worry. Hackers could take control of a satellite and steal intellectual property, redirect data flows or cause a collision. The satellite industry has been slow to respond to such concerns. But as more of the world’s population comes to rely on space for access to the Internet, the need for action intensifies. Measures will surely be taken to protect network security.

The third issue follows from the first two. If a simple mistake or a cyber-attack can cause a chain reaction which wipes out hundreds of billions of dollars of investment, who is responsible for that? Now the plans of firms, wishing to operate large numbers of satellites are being studied. But there is a long way to go before the risks are well understood, let alone priced.

As space becomes more commercialized, mind-bending prospects open up: packages moved across the planet in minutes by rocket rather than by plane, equipment sent to other small planets, passengers launched into orbit and beyond. All that and more may come one day. But such activities would raise the same questions as LEO satellites do. They must be answered before the space economy can truly develop.