In the traffic lights,red means "stop",green means "go",and yellow means "hurry": Why those colors, though? Why not blue,purple,and brown?The following are transponded from others WeChat.

●Red is an inherited symbol from railroads

    Red symbolizes danger in many cultures,which makes sense,considering it has the longest wavelength of any color,meaning you can see it from a greater distance than other colors.Red has meant "stop" since long before cars existed,with railway signals use of red dating bake to the days when mechanical arms lifted and lowered to indicate whether the rail ahead was clear.So that one's simple.

●Green meant "caution" at first

    Green's role in lights has actually changed dramatically over time.Its wavelength is next to (and shorter than) yellow's,meaning it's still easier to see than any color other than red and yellow.Back in the early days of railway lights,green originally meant "caution",while the "all-clear" light was,well,clear or white.Trains,of,course,take an unlimitedly long time to stop,and legend has it that several disastrous collisions happened after an engineer mistook stars in the night horizon for an all-clear.Thus,green became "go",and for a long time,railways used only green and red to signal trains.

●Yellow means "caution" because it's almost as easy to see as red

    From the earliest days of motoring up until the mid-1900s,not all stop signs were red-many were yellow, because at night it was all but impossible to see a red stop sign in a poorly lit area.The yellow stop-sign craze began in Detroit in 1915,a city that five years later installed its first electric traffic signal,which happened to include the very first amber traffic light,at the corner of Michigan and Woodward Aves.

    When I was about 12, I had an enemy, a girl who liked to point out my shortcomings (缺点). Wee k by week her list grew: I was very thin, I wasn't a good student, I talked too much, I was too proud, and so on. I tried to hear all this as long as I could. At last, I became very angry. I ran to my father with tears in my eyes.

    He listened to me quietly, then he asked. “Are the things she says true or not? Janet, didn't you ever wonder what you're really like ? Well, you now have that girl's opinion. Go and make a list of everything she said and mark the points that are true. Pay no attention to the other things she said.”

    I did as he told me. To my great surprise, I discovered that about half the things were true. Some of them I couldn't change (like being very thin), but a good number I could—and suddenly I wanted to change. For the first time I went to a fairly clear picture of myself.

    I brought the list back to Daddy. He refused to take it. “That's just for you,” he said. “You know better than anyone else the truth about yourself. But you have to learn to listen, not just close your ears in anger and feeling hurt. When something said about you is true, you'll find it will be of help to you. Our world is full of people who think they know your duty. Don't shut your ears. Listen to them all, but hear the truth and do what you know is the right thing to do.”

    Daddy's advice has returned to me at many important moments. In my life, I've never had a better piece of advice.

    Princeton University is a vibrant (充满生机的) university. It is the fourth oldest college in the United States and an independent institution that provides undergraduate and graduate instruction in the arts and humanities, social sciences, natural sciences, and engineering. As a well-known research university, Princeton seeks to achieve the highest levels in the discovery and spread of knowledge and understanding. At the same time, Princeton is different among research universities in its commitment to undergraduate teaching.

    Academics

    Faculty (教员), including full time, part time and visiting: 1,238 (spring 2016)

Undergraduate student-to-faculty rate: 5:1

    Departments: 36

    Schools within the University: School of Architecture, School of Engineering and Applied Science, Woodrow Wilson School of Public and International Affairs

    Library

    Princeton University Library consists of the Firestone Library and nine buildings across campus. The library's collections include more than 8 million books and impressive rare books, prints and other materials that require special handling. The library's extensive electronic resources include databases and journals, images and digital maps. Exhibitions of the library are free and open to the general public.

    Campus Life

    A vast range of cultural9 educational, athletic and social activities are available to Princeton students. Getting involved in campus life is the quickest way to become a part of the University community, and to create one's own Princeton experience. Campus life activities are built around the concepts of encouraging each community member to display his or her talents and to learn to respect all members of our community.

    Aid Program

    Our aid program is designed to encourage all qualified students—regardless of financial circumstances-to consider applying for admission to Princeton. Any family who feels they may need help to pay for a Princeton education is welcome to apply for aid.

    For more information, please visit: http://www. Princeton.edu.

With the clicking of walking sticks and determined steps, a long line of walking group along the winding road is a fantastic sight. Almost each of the walkers is using some kind of fitness tracker. A few Fitbits, some Xiaomi wrist bands (手环), a couple of phone apps and some other pedometers (计步器) — and all, they say, are counting their steps.

    Fitness trackers are in. Sales figures for 2016 released by Internet Data Center (IDC) indicated 25% market growth compared to the previous year, with Fitbit taking the lion's share, followed by the brand Xiaomi.

    However, the wearables market has had a rollercoaster ride in recent months. Jawbone, once a popular fitness tracker brand, announced that it is leaving the consumer market. Microsoft has removed its Fitness Band on its online store although it is still available on retail (零售) giant Amazon. Fitbit remains a key brand name at the heart of the fitness tracker revolution. But it is recently reported to be cutting down on workers, and its founder James Park said it experienced “softer than expected” sales recently.

    Counting steps is probably the most common use of wearable devices (可穿戴设备), but recently experts have questioned whether the golden goal of walking 10,000 steps a day is actually worthwhile, and a US study concluded that health trackers did not aid weight loss.

Analyst Ben Wood from CCS Insight used to wear a fitness tracker on either wrist. Now, however, his concern is about users'experience — these devices don't tell you anything new after a while. There are also battery problems and many of the older and cheaper varieties aren't waterproof (防水的).

    Chester is one of the best cities in the UK. As soon as you arrive in Chester you will appreciate the city's unique atmosphere and sense his history. Founded by the Romans over 2,000 years ago, much of the Roman influence remains and Chester's city walls are the most complete in Britain. Combined with history and heritage (遗产), Chester is a lively city full of bars, pubs, clubs, hotels, and restaurants for you to discover, attracting you to visit again and again.

    Travelling to Chester: Chester is easily accessible by many means of transport—whether you are travelling by rail, car, bus or plane. Please check our route planner below to help you plan your journey to Chester. Once you arrive in the city there are numerous car parks; however, during rush hours the easiest way to travel is by bus.

    Hotel: From bed & breakfast to the luxury of Chester's only five star hotel, Chester has all covered. Whether your trip is for business or pleasure, your room is just a click away!

    Sightseeing and Tours: The best way to see Chester is by a guided tour. If you join one, you still have a variety to choose from. Whether you choose the traditional guided walk, to be guided around Chester historical landmarks by bus or to take a boat down the River Dee, you will sure enjoy the delights of Chester.

    Have you ever been to a music festival? Well if you live in the UK, the answer is probably yes. The number of festivals has grown greatly over the last few years and now there are around 200 every summer. So let's look at the history of four famous festivals.

    The Glastonbury Festival is a five-day festival of contemporary (当代的) performing arts held most years in Somerset, in the south-west of England. There are a rock and pop stage, a jazz stage, the Avalon stage, a theatre comedy stage, a cinema tent, a dance tent and a circus (马戏团). The festival started in1970and about 120, 000 people go to it every summer.

    The Reading Festival is truly world-class with rock and pop bands (乐队) appearing from all over the world, particularly (尤其) the USA. About 80, 000 music fans go to Reading every August Bank Holiday. The festival first came to its present site on the banks of the River Thames in Reading in 1971, when it moved from Plumpton in Sussex. It is still on the same site over 47 years later!

    WOMAD stands for World of Music, Arts and Dance and was the idea of rock musician Peter Gabriel to promote (宣传) world music. The WOMAD Festival started in 1982 and takes place in July at Charlton Park, near Malmesbury in Wiltshire, and you can see different bands and musicians from all over the world. The festival welcomes over 26, 000 visitors each year.

    The one-day Monsters of Rock Festival at the National Bowl in Milton Keynes was first held in 1980 and gave visitors the chance to hear the very best of hard rock and heavy metal. There were no festivals between 1996 and 2003 as a result of changing musical fashions, but now it has returned and grown into a two-day festival with a campsite for the 30, 000 people who go there in summer days.