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.

    A music festival is a community event focusing on live performances of singing and instrument playing that is often presented with a theme. On the list are the music festivals for fans around the world. Find your favorite now!

    Field Day

    January 1, 2018. Sydney

    Field Pay means New Year's Day for young people in Sydney. Seen as the city's original multi－stage party,, it's a gathering of friends coming together for a great fun - filled first day of the year. There's an air of hope and positive energy on a perfect summer's day.

    The Envision Festival

    February 22 – 25, 2018, Uvita

    The Envision Festival is an annual gathering in Costa Rica that aims to provide an

opportunity for different cultures to work with one another to create a better community. The festival encourages people to practice art, music, dance performances, and education. Meanwhile, our connection with nature is expected to be strengthened.

    The McDowell Mountain Music Festival

    March 2 - 4, 2018, Phoenix

    The McDowell Mountain Music Festival is Phoenix、musical celera ,on of community culture. Since its founding in 2004 f it is the only 100% non – profit music festival designed to support, entertain and educate the community. The festival attracts thousands of visitors each year from around the country, and it is an opportunity to experience true culture.

    The Old Settler's Music Festival

    April 19 - 22, 2018, Dale

    The Old Settler's Music Festival is a nationally known music festival for American music. The festival is held in the country of Texas at the height of the wild flower season. The Old Settler's Music Festival offers great music and activities for the whole family.

    A new discovery may change how scientists think about prehistoric humans. Human history is more of a war movie than a romantic comedy, at least as far as other animals are concerned; we may be causing one of the planet's great extinction events at the moment. But a recent discovery means humans might not be as destructive as we thought.

    Large animals have a history of disappearing when humans move to their areas. Scientists have long believed that humans simply hunted big animals because people are really good at hunting. For example, scientists thought humans arrived in Madagascar around 4,000 years ago, but only two thousand years later, giant lemurs, giant tortoises and elephant birds disappeared from the island. Many scientists thought humans had something to do with that rapid drop in biodiversity(生物多样性).

    At least, that's what scientists thought until a group of researchers dug up a lot of bones in Madagascar recently. These bones belonged to the elephant bird, a kind of extinct bird that weighed up to 1,000 pounds. The huge bones were covered in cuts that clearly came from a human hunter. The researchers found that the humans had killed the birds 10,000 years ago...Thousands of years before scientists believed humans had come to the island.

    "Our research provides evidence of human activity in Madagascar more than 6,000 years earlier than suspected, which shows that a different extinction theory is required to understand the huge biodiversity loss that has happened on the island." explained James Hansford, one of the researchers. "Humans seem to have coexisted with elephant birds and other now-extinct species for over 8,000 years, clearly with limited negative influence on biodiversity for most of this period."

    If humans lived among large animals for thousands of years without wiping them out, then maybe our species can't wipe other species out. Rather, extinction is more of a habit we've learned. Perhaps we can unlearn it too.

    When my family moved to the United States from Colombia, I was 9 years old and knew little about English. As time passed, teachers finally knew all of their students and slowly everyone began to head inside, except for me. No one called out my name, and no one seemed to know I existed. I spent the next month in my new classroom quietly. I felt a wave of fear, loneliness and sadness came over me.

    It turned out the school administration never cared that I didn't speak English, but something else was teaching me English. Every morning when my aunt drove me to school and picked me up, she always had 106.7 Light FM on. It was this station that introduced my young ears to the English sounds of R&B, soul, jazz and much more.

Because of Sabrina the Teenage Witch, I learned the difference between "witch" and "which". While watching the TV show South Park, I was attracted by the funny characters. I related "You bastards!” to anger and saved it in my mental word bank. In fact, thanks to pop culture, the world of English became not so hard to me while it was being turned down at school.

    I also learned how to express my emotions thanks to pop culture. One day at school, we were taking a math quiz and the whole class was quiet. Suddenly, the tip of my pencil broke and I yelled, “You bastards!" Everyone held their breath in surprise and I laughed to myself because something at that moment told me I had just learned my first bad word in English.

    Four months passed before the school placed me into an ESL program. By this time, I was speaking broken English and making myself understood. Finally, I learned how to speak and write English at a more advanced level, and I owe it all to pop culture.

    Dujiangyan is the oldest man­made water system in the world, and a wonder in the development of Chinese science. Built over 2, 200 years ago in what is now Sichuan Province in Southwest China, this amazing engineering achievement is still used today to irrigate over 6, 000 square kilometers of farmland, take away floodwater and provide water for 50 cities in the province.

    In ancient times, the region in which Dujiangyan now stands suffered from regular floods caused by overflow from the Minjiang River. To help the victims of the flooding, Li Bing, the region's governor, together with his son, decided to find a solution. They studied the problem and discovered that the river most often overflowed when winter snow at the top of the nearby Mount Yulei began to melt as the weather warmed.

    The simplest fix was to build a dam, but this would have ruined the Minjiang River. So instead Li designed a series of channels built at different levels along Mount Yulei that would take away the floodwater while leaving the river flowing naturally. Better still, the extra water could be directed to the dry Chengdu Plain, making it suitable for farming.

    Cutting the channels through the hard rock of Mount Yulei was a remarkable accomplishment as it was done long before the invention of gunpowder and explosives. Li Bing found another solution. He used a combination of fire and water to heat and cool the rocks until they cracked and could be removed. After eight years of work, the 20­metre­wide canals had been carved through the mountain.

    Once the system was finished, no more floods occurred and the people were able to live peacefully and affluently. Today, Dujiangyan is admired by scientists from around the world because of one feature. Unlike modern dams where the water is blocked with a huge wall, Dujiangyan still lets water flow through the Minjiang River naturally, enabling ecosystems and fish populations to exist in harmony.

    Do you want to do some volunteer work while exploring Africa? Then join in our 21-Day Flagship Program. Step onto the flat, sandy land of Ghana, and you'll immediately hear the laughter of children everywhere. This laughter will be the constant of your trip and a steady source of energy while you volunteer among one of Africa s kind communities.

    Community Service

    Volunteer in primary schools, working with children of different ages to help improve their English skills, tutor those who might be falling behind and contribute to each school's needs, including making improvements to the facilities. Split your time between teaching and campus refurbishment (翻修) projects to serve every aspect of the school, and learn all about education in Ghana.

    Hands-on Learning

    Participate in workshops such as batik cloth dyeing (蜡染), drumming, dancing and crash courses in the native language, Ewe or Krobo. You'll be given a Ghanaian name by the local chief of your village, and visit a seamstress (女裁缝) to have custom clothing made out of colorful fabrics you purchase. On the 21-Day Flagship Program, you'll hear about the nation's history as a center of the slave trade, and visit Fort Prinzenstein to truly understand the weight of this topic.

    Adventure

    You'll also experience the natural surroundings of Ghana with a beautiful waterfall hike: On your 21-Day Flagship Program, go on a two-night trip where you'll get to visit a monkey shelter.

    Lodging

    Global Leadership Adventures (GLA) operates two Home Bases for the 21-day program. Both are located outside of the capital city of Accra in rural village settings. Accommodations are basic, but clean and safe. Students sleep in rooms with roommates, and have access to shared bathrooms with cold-water showers.

    Dates

    June 26-July 16, 2019

    July 9-July 29, 2019

    July 20-August9, 2019

    Duration: 21 days

    Tuition: $5,399

    Community Service Hours: 60

    For more information, please call 1-858-771-0645 or send an email to info@experiencegla.com.