Chinese scientists recently have produced two monkeys with the same gene, Zhong Zhong and Hua Hua, using the same technique that gave us Dolly the sheep. These monkeys are not actually the first primates（灵长类）to be cloned. Another one named Tetra was produced in the late 1990s by embryo（胚胎）splitting, the division of an early-stage embryo into two or four separate cells to make clones. By contrast, they were each made by replacing an egg cell nucleus（原子核）with DNA from a differentiated body cell. This Dolly method, known as somatic cell nuclear transfer（SCNT）, can create more clones and allows researchers greater control over the edits they make to the DNA.

    Success came from adopting several new techniques. These included a new type of microscopy to better view the cells during handling or using several materials that encourage cell reprogramming, which hadn't been tried before on primates. Still, the research process proved difficult, and many attempts by the team failed. Just two healthy baby monkeys born from more than 60 tested mothers. This leads to many researchers' pouring water on the idea that the team's results bring scientists closer to cloning humans. They thought this work is not a stepping stone to establishing methods for obtaining live born human clones. Instead, this clearly remains a very foolish thing to attempt, it would be far too inefficient, far too unsafe, and it is also pointless.

    But the scientists involved emphasize that this is not their goal. There is now no barrier for cloning primate species, thus cloning humans is closer to reality. However, their research purpose is entirely for producing non-human primate models for human diseases; they absolutely have no intention, and society will not permit this work to be extended to humans. Despite limitations, they treat this breakthrough a novel model system for scientists studying human biology and disease.

    Many years ago, people relied on the sun, the moon and stars to find their way around. Later, the compass was introduced. And now, we have satnav（卫星导航）systems to guide us. A satnav system uses groups of satellites to show the user's location. They send information to a receiver, such as a smartphone, to show us where we are.

    The earliest built satnav system is the Global Positioning Satellite System, which belongs to the US. Then there is Russia's Global Navigation Satellite system，the European Union's Galileo and China's own satellite navigation system, Beidou.

On October 18, 2017, an ARJ21-700 plane, which was the first domestically（国内地） produced jet equipped with the Beidou navigation system, successfully completed a test flight. The results showed the performance of the system developed by China matches that of similar systems produced abroad, according to the Commercial Aircraft Corporation of China.

    Since its introduction in 2000, the Beidou navigation system has been increasing numbers of applications linked to everyday life, from shared bikes to farming.

When it comes to shared bikes, smart locks that support Beidou chips offer more accurate positioning than others, making it easier to find a bike.

    Farmers can use Beidou-enabled tractors to plow（犁）the soil and use unmanned aircraft with Beidou to sow seeds, which can improve efficiency and make better use of resources. Beidou's farming applications have spread from Heilongjiang Province to Beijing, Liaoning, Shanxi, Hubei and other regions across China.

    With its many uses, the Beidou navigation system is even playing a big role in the Belt and Road Initiative（一带一路）. “To date, the Beidou system has covered most parts of the Asia-Pacific region, as well as countries along the Silk Road Economic Belt and the 21^st Century Maritime Silk Road,” said Yang Changfeng, chief designer of the Beidou system.

    Today, there are more than 20 Beidou satellites above our heads, and China plans to launch even more this year to expand the Beidou network to better serve the Belt and Road Initiative.

    “As Beidou expands its overseas reach, it will be increasingly popular in the logistics（物流） industry,” said Miao Qianjun, Secretary General of the navigation services association. “Ships, for example, can use it to position themselves while sailing across oceans to European countries, no longer limited to Southeast Asian regions in the near future.

Are we alone in the universe? A team of scientists announced on January 6, 2015 that they had identified eight planets beyond our solar system, three or four of which orbit in their stars' "Goldilocks Zone" — the region where temperatures are not too hot or too cold for water, which is a necessary ingredient for life as we know it, to exist liquid form. This may be good news for people hoping that Earth is not the only inhabited world in the universe.

    The scientists, led by Dr. Guilermo Torres of the Harvard-Smithsonian Center for Astrophysics, made the discoveries using data collected by the planet-seeking Kepler telescope.

    NASA launched Kepler in 2009. Since then, the telescope has identified more than 1,000 planets outside of our solar system. Torres and his team analyzed the data about the eight newly discovered world to determine which ones are most likely to be similar to our Earth.

    Among the new discoveries, the scientists say the planets called Kepler438b and 442b are the closest to Earth. Kepler 438b is just about 10% larger than our planet, and gets 40% more of its energy from its star than Earth receives from the Sun. Temperatures there would be about 140 degrees. Kepler 442b is about 33% larger than Earth, but receives 30% less energy from its star. That would make it a potentially chillier world than our own. Torres says it is possible for life to exist and survive in either of those temperatures, but for that to happen, these planets would need to have another key ingredient for life: a heat-trapping atmosphere like Earth's.

    While these findings add to the possibility that life exists beyond Earth, Torres cautions against drawing conclusions, “We are not claiming they are inhabited,” he says. In fact, these planets are so far away that the scientists cannot observe them directly, which can be explanation for why for now it remains unknown whether these planets contain life. But the discovery of planets in their stars' habitable zones suggests that somewhere out there, some form of alien life may have taken hold.

    There's a song by the great Jamaican singer Bob Marley called So Much Trouble In The World. Marley understood that part of the reason why there are so many problems in the world is the lack of tolerance between people. The UN understands this too—that's why it made Nov 16 "International Day for Tolerance".

    But first of all, what is tolerance? French philosopher Voltaire (1694—1778) can give us some help. According to him, tolerance "is the consequence of humanity. We are all formed of frailty (脆弱) and error; let us pardon each other's folly—that is the first law of nature."

    Nobody's perfect. When we're tempted to criticize another person, we should perhaps remember our own imperfections first.

    Very often, people don't realize that they're intolerant. This is because intolerance has a lot to do with ignorance. For example, the UN's campaign is in part about the treatment of females by males. But often, the behavior of men toward women is intolerant because men don't put themselves in the shoes of women.

    It's worth thinking a little about the words "tolerance" and "intolerance". Are they the best words to describe the evils of which we're speaking here? To agree to be "tolerant" of someone isn't necessarily a very respectful thing. When someone is tolerated, it implies that there's something wrong with them.

    But it seems wrong that people should agree to "tolerate" people with black skin, for example. And should women think they have received the respect they are due when men agree to "tolerate" them?

    Still, what Voltaire said stands: We humans are not perfect and this weakness is something that we all share. That's the reason we should be tolerant.

    It's a little like generosity. We can give things to another person, and we can also give our forgiveness. Bob Marley understood this. In the song mentioned above, he advised: "Write your love on a rock so it stays for eternity; write your hate in the sand so the waves will wash it away."

    The American dream is the faith held by many people in the United States of America that through hard work, courage, creativity and determination, they can achieve a better life for themselves. More specifically, they agree on how to get ahead in America: get a college education, find a reliable job, and buy their own house. But do Americans still believe in that path, and if they do, is it attainable?

    The most recent National Journal poll(民意测验，投票) asked participants about the American dream, what it takes to achieve their goal, and whether or not they felt the control over their ability to be successful. Obviously, the results show that today, the idea of the American dream and what it takes to achieve it looks quite different from it did in the late 20th century. By the large, people felt that their actions and hard work — not outside forces — were the deciding factors in how their lives turned out. But the participants had definitely mixed feelings about what actions make for a better life in the current economy.

    In the last seven years, Americans have grown more pessimistic about the power of education to lead to success. Even though they see going to college as a fairly achievable goal, a majority 52 percent think that young people do not need a 4-year college education in order to be successful.

    Miguel Maeda, 42, who has a master's degree and works in public health, was the first in his family to go to college, which has allowed him to achieve a sense of financial stability(稳定) his parents and grandparents never did. While some, like Maeda, emphasized the value of a degree rather than the education itself, others still see college as a way to gain new viewpoints and life experiences. Sixty-year-old Will Fendley, who had a successful career in the military and never earned a college degree, think “personal drive” is far more important than just go to college. To Fendley, a sense of drive and purpose, as well as an effective high-school education, and basic life skills, like balancing a checkbook(支票簿), are the necessary elements for a successful life in America.

"Don't get dirty!" was once often shouted by parents angrily watching their children ruin their best clothes. It was unavoidable that children's whites would turn brown before the day was over. 

Today, many parents may secretly wish their children had the chance to pick up a bit of dirt. With the rise of city life, and the attraction of video games and social media, contact with nature is much less than in the past. For many, there is simply no opportunity to get muddy. According to recent research, the dirt outside is teaming with friendly microorganisms (微生物) that can train the immune (免疫的) system and build the body against illnesses, such as anxiety. 

These findings show that outdoor exercise is not only beneficial because of the chance to run around free—but that certain natural materials, such as soil and mud, also have powerful microorganisms which have positive effect on children's health. Outdoor play can also offer valuable learning experiences. For example, the act of rubbing and shaping materials like mud or sand can help children develop their senses and movement. 

Such activities—away from the house or classroom—may also help children to find ways to deal with emotions that may be hard to explore in other environments. So-called "Sandtray Therapy (沙盘疗法)", which includes using sand to express one's thoughts and feelings, is an accepted form of guidance for children who are struggling to speak out their inner emotions. 

Surprisingly, people who spent most of their childhood in the countryside show a better reply to stressful events like public speaking compared with those who grew up in cities. "The people who grew up in cities are kind of ‘walking time bombs' when facing the stress we meet today. However, people who have spent lots of time in nature since childhood are generally stronger in recovery and more positive." says Christopher Lowry, a professor of University of Colorado Boulder.