For as long as I can remember, I've always wanted a personal motto. I wanted a saying that I could really try to live my life by. I mean all the humorous book and storybook heroes always have a personal principle they follow. Good manners! Courage! Keenness! But a part of me could never get myself to create my own motto because I never knew where to start and I never thought I could give one.

    “With great power comes great responsibility.” is a quote by the great writer and philosopher, Voltaire. More familiar, it makes an appearance in the modern day movie performance of the superhero Spider-Man. This saying provides a sense of responsibility for those with actually limitless power.

    “Be good to others and others will be good to you.” is another well-known proverb that has roots in almost all of the major religions. Although it is less practiced today than it is lectured, it is a powerful and good motto to live by. Kindness, in this sense, is the final power in judging every action.

    My personal motto today has an idea – being efficient. Through my limited knowledge, I have come to find that this is simply the best way for me to give insight about who I am and what I believe in.

 Efficiency is a quality that everyone desires for, right? Who doesn't want to be able to not only work fast but to achieve great results? To some, it may appear to be a frightening journey. But to me, it means that I have a lifelong journey to improve the methods and ideas with which I come near my tasks.

    Regardless of what motto you want to live by, I believe that everyone should have one, or two or more. These are all symbols of a perfect story of us, in our own view. And it immediately provides insight to the type of person we were, we are and what we strive to be. We are never meant to be perfect, but it is important to try and live by a belief that will help us reach our potential. All you have to do is know what your excitement is and live by it.

    In a recent announcement, Harvard and the Massachusetts Institute of Technology（MIT）said that they have joined forces to offer free online courses in an effort to attract millions of online learners worldwide.

    Beginning this fall, a number of courses developed by teachers at both universities will be offered online through a new $60 million program, known as edX. “Anyone with an Internet connection anywhere in the world can use our online courses,” Harvard President Drew Faust said during a meeting to announce the plan.

    MIT has offered a program called OpenCourseWare for ten years that makes materials from more than 2,000 classes free online. It has been used by more than 100 million people. In December, the school announced it also would begin offering a special certificate, known as MITx, for people who complete certain online courses. Harvard has long offered courses to a wider population through a similar program.

    The MITx will serve as the foundation for the new learning platform.

    MIT President Susan Hockfield said more than 120,000 people signed up for the first MITx course. She said Harvard and MIT hope other universities will join them in offering courses on the open-source edX platform.

     “Fasten your seatbelts,” Hockfield said.

    Other universities, including Stanford, Yale and Carnegie-Mellon, have been experimenting with teaching to a global population online.

    The Harvard-MIT program will be monitored by a not-for-profit（非盈利的）organization based in Cambridge, to be owned equally by the two universities. Both MIT and Harvard have provided $30 million to start the program. They also plan to use the edX platform to research how students learn and which teaching methods and tools are most successful.

    Palaces are known for their beauty and splendor, but they offer little protection against attacks. It is easy to defend a large building, but usually these buildings are not designed with the comfort of a king in mind. When it comes to structures that are both beautiful and defensive, the European castle is a big success.

    Castles were originally built in England by the Normans in 1066. They built towers and walls to secure the land they had taken. These castles provided the Normans with a quiet and safe place. They also served as bases of operation for attacks. In this way castles served both defensive and offensive roles. Besides, castles served as offices for governors. Those that were socially beneath the governor would come to report affairs and express their respect. They would address problems, handle business, feast, and enjoy festivities in castles. So castles served as social centers as well.

    The first castles were made from earth and wood, and they were likely to suffer from attacks by fire. Then wooden castles were gradually replaced by stone, which greatly increased the strength of these towers and walls. However, attackers could throw flaming objects into castles through the windows or burn the wooden doors. This led to moving the windows and entrances off of the ground floor and up to the first floor to make them more difficult to access.

    During the Middle Ages, attacks increased in regularity, so castle defenses were updated. Arrow-slits were added. They were small holes in the castle, which allowed defenders to fire without being hurt. Towers were built from which defenders could provide fire on both sides. The towers were connected to the castle by wooden bridges, so that if one tower fell, the rest of the castle was still easy to defend. A lot of rings of castle walls were constructed, so that even if attackers went past one wall, they would be caught on a killing ground between inner and outer walls. All of these increased the defense of castles.

    The end of castles can be attributed to gunpowder. During the 15th century, artillery, a kind of large guns, became powerful enough to break through stone walls. This greatly made the role of castles less effective. Though castles no longer serve their original purposes, remaining castles receive millions of visitors each year who wish to experience the situations of ancient times.

    It's undeniable that spending time outdoors and in nature lifts our spirits and makes us feel more centered and at peace. When we breathe in fresh air, and enjoy the beauty of trees, streams and oceans, we naturally tend to feel more connected to ourselves and others.

Over the past decade, scientists have been exploring why nature — and dirt specifically — is such a powerful tool in improving our mood. According to researchers, the secret may lie in the microbes (微生物)of the soil. One bacterium specifically—-Mycobacterium Vaccae (M. Vaccae) —has been identified as having the power to affect our moods and cognitive function as well.

    Experiments conducted at Sage Colleges in New York found that contact with M. Vaccae can increase serotonin levels in the brain — a chemical that is associated with higher levels of happiness, increased focus, and reduced anxiety. In order to explore how the bacteria can improve learning, researchers Dory Mathews and Susan Jenks experimented with mice in a maze. Mice that ingested the bacteria navigated the maze twice as fast as the control group and proved less anxious as well.

    Humans can absorb M. Vaccae just by playing in the dirt. We take in it when we breathe, we consume it in organic vegetables, and it can also enter our bloodstream through skin contact, especially where we have open cuts. This may explain why children in school perform better after break.

    Neuroscientist Christopher Lowry at the University of Bristol in England believes that he has identified why this incredible bacterium works. "What we think happens is that the bacteria activate immune cells, which release chemicals called cytokines that then act on receptors on the sensory nerves to increase their activity.”

    Beyond the power of M. Vaceae, scientists have been proving for decades that exposure to dirt, and the huge number of microbes found in dirt, can strengthen our immune system. When our body comes into contact with bacteria, it stores die information in a type of library and can then use that information to fight sickness and infection more effectively.

    Happiness, focus, less anxiety… I'll take a double dose of dirt; please!

    There is a popular belief among parents that schools are no longer interested in spelling. No school I have ever taught in has ever ignored spelling or considered it unimportant as a basic skill. There are, however, different ideas about how to teach it, or how much priority (优先) it must be given over general language development and writing ability. The problem is how to encourage a child to express himself freely and confidently in writing without holding him back with the complexities (复杂性) of spelling. That's why teachers often encourage the early use of dictionaries and pay attention to content (内容) rather than spelling.

    If spelling becomes the only focus of his teacher's interest, clearly a bright child will be likely to "play safe". He will tend to write only words within his spelling range, choosing to avoid adventurous language.

    I was once shocked to read on the bottom of a piece of writing about a personal experience. "This work is terrible! There are far too many spelling mistakes and your writing is terrible." It may have been a sharp comment on the pupil's spelling in writing, but it was also a sad sign that the teacher had failed to read the composition, which contained some beautiful expressions of the child's deep feelings. The teacher was not wrong to draw attention to the mistakes, but if his priorities had centered on the child's ideas, an expression of his disappointment with the spelling would have given the pupil more encouragement to seek improvement.

    Finland is the happiest place on Earth, according to the 2018 World Happiness Report of 156 nations.

    The report, released Wednesday by the United Nations'Sustainable Development Solutions Network, ranks the countries of the world based on six different categories of well-being: income, freedom, trust, life expectancy, generosity and social support. This year's report also pays special attention to the happiness of each country's immigrants.

    The U.S. dropped four spots from 2017 and landed in 18th place, and last year's winner, Norway, came in second place — followed by Denmark, Iceland and Switzerland.

    “The top five countries all have almost equally high values for the six factors found to support happiness, and four of these countries—Denmark, Switzerland, Norway and now Finland — have been in first place in the six World Happiness Report rankings since the first report" in 2012, "co-editor John Helliwell told CNN. “In a division with such excellent teams, changes in the top spot are to be expected."

    Rounding out the top 10 happiest countries was Canada in sixth place, then New Zealand, Sweden and Australia. The order of the top 10 nations changed from the 2017 list but the countries did not, according to the report. They were also 10 of the 11 top spots in the immigrant happiness category (including Mexico — 24th overall, but 10th in immigration).

    "The most striking finding of the report is the remarkable consistency between the happiness of immigrants and the locally born," Helliwell said in a statement. "Although immigrants come from countries with very different levels of happiness, their reported life evaluations resemble those of other residents in their new countries. Those who move to happier countries gain, while those who move to less happy countries lose."

    Other major world powers placed in significantly low spots on the list. Germany came in 15th, the UK was 19th — followed by Japan in 54th place, Russia in 59th and China in 86th.

    The report, based on surveys completed by citizen volunteers, came just under a week before World Happiness Day on March 20, when the UN declared to recognize "the relevance of happiness and well-being as universal goals and aspirations in the lives of human beings around the world and the importance of their recognition in public policy objectives"