Teachers' Day is, interestingly, not celebrated on the same day all over the world. In some countries it is marked by a holiday; in others it is a working day.

    International Teachers' Day is celebrated on October 5. Being held ever since 1994, it is in honor of teachers' organizations worldwide. Its aim is to encourage supports for teachers and to meet the needs of students.

China — In 1939, Teachers' Day was set for August 27, Confucius' birthday. In 1951, the celebration was stopped. However, it was founded again in 1985, and the day was changed to September 10.

India — Teachers' Day is celebrated on September 5 in honor of Dr. Sarvepalli Radhakrishnan, the second president of India, whose birthday falls on that day.

    Russia — In Russia, Teachers' Day was celebrated on the first Sunday of October between 1965 and 1994. Since 1994, the day is observed on October 5, just the same day as World Teachers' Day.

    The US - In the US, Teachers' Day is non-official holiday. It is celebrated on the Tuesday of the first full week of May. A number of activities are organized in schools to honor teachers. The celebrations can continue for the whole week of May.

Thailand — In Thailand, National Teachers' Day is celebrated every year on January 16. The first Teachers' Day was held in 1957. The day is a holiday in schools.

    "How are you" is a nice question. It's a friendly way that people in the United States greet each other. But "How are you?" is also a very unusual question. It's a question that often doesn't have an answer. The person who asks "How are you?" hopes to hear the answer "Fine.", even if the person's friend isn't fine. The reason is that "How are you?" isn't really a question and "Fine." isn't really an answer. They are simply other way of saying "Hello!" or "Hi!".

    Sometimes, people also don't say exactly what they mean. For example, when someone asks, "Do you agree?", the other person might be thinking, "No, I disagree. I think you're wrong…"But it isn't very polite to disagree strongly, so the other person might say "I'm not sure…". It's a nice way to say that you don't agree with someone.

    People also don't say exactly what they are thinking when they finish talking with other people. For example, many talks over the phone finish when one person says "I've to go now." Often, the person who wants to hang up gives an excuse," Someone is at the door." "Something is burning on the stove." The excuses might be real, or it might not. Perhaps the person who wants to hang up simply doesn't want to talk any more, but it isn't polite to say that. The excuse is more polite, and it doesn't hurt the other person.

    When they are greeting each other, talking about an idea, or finishing a talk, people often don't say exactly what they are thinking. It's an important way that people try to be nice to each other, and it's also a part of the game of language.

    Here are some great people and their achievements.

    Mary Anderson ­ windscreen wiper.

    Back on a freezing winter's day in 1902, Mary Anderson was travelling by train through New York City. Snow was falling, forcing the driver to stop repeatedly and get out to clear it. Each time the door opened, Mary suffered a gust of sub-zero air. She had an idea: why not make some kind of a rubber blade that could be operated from inside the vehicle? And that's exactly what she did.

    Josephine Cochrane ­ dishwasher

    The dishwasher dates back even earlier to the 19th century, and to the dinner parties thrown by a lady called Josephine Cochrane. As a frequent host, she wanted a machine that could wash dishes faster than people. Her response was to develop what was to become the first commercially successful dishwasher. Interestingly, innovation was in her blood: her grandfather had invented the steamboat.

    Stephanie Kwolek ­ Kevlar

    Kevlar is the lightweight fibre used in bulletproof vests. The material is used by millions every day and has saved countless lives. The super tough fabric is also used in objects ranging from gloves to airplanes. Incredibly, its strength-to-weight ratio(比强度) is five times higher than steel. Again, it was invented by a woman, the American chemist Stephanie Kwolek, in 1964.

    Grace Hopper ­ first compiler(编译程序)

    One of the most important inventions of the 20th century must surely be the computer programme. The world of programming is unbalanced in terms of gender. Men vastly outnumber women, and take home around 30% more pay than their female counterparts on average. But back in the 1940s and 1950s, women were at the forefront of this new field. Grace Hopper is credited with inventing the first compiler in 1952, which serves as the bridge between code and the binary(二进制的) ones and zeros understood by computers.

    I was ten when my father first sent me flowers. I had been taking ballet lessons for four months, and the school was giving its yearly performance. As a member of the beginners' chorus group, I was surprised to hear my name called out at the end of the show along with the leading dancers and to find my arms full of red roses. I can still feel myself standing on that stage, seeing my father's big smiles.

    Those roses were the first of many bunches accompanying all the milestones in my life. Getting all those roses was wonderful, but they brought a sense of embarrassment. I enjoyed them, but I also felt they were too much for my small achievements.

    Not for my father. He did everything in a big way. Once, when mother told him I needed a new party dress, he brought home a dozen. His behavior often left us without money for other more important things. Sometimes I would be angry with him.

    Then came my 16th birthday. It was not a happy occasion. I was fat and had no boyfriend. And my well-meaning father furthered my suffering by giving me a party. As I entered the dining room, there on the table next to my cake was a huge bunch of flowers, bigger than any before.

    I wanted to hide. Now everyone would think my father had sent flowers because I had no boyfriend to do it. Sweet 16, and I felt like crying. But my best friend, Jenny, whispered, "Boy, you're lucky to have a father like that."

    As the years passed, other occasions—birthdays, awards, graduations—were marked with Dad's flowers. Those flowers symbolized his pride, and my success. As my fortunes grew, my father's health became worse, but his gifts of flowers continued until he died. I covered his coffin with the largest, reddest roses I could find.

    Often during the dozen years since, I felt an urge to buy a big bunch to fill the living room, but I never did. I knew it would not be the same.

    Then one birthday, the doorbell rang. I was feeling blue because I was alone. My husband and my two daughters were away. My 10-year-old son, Tommy, had run out earlier with a "see you later". So I was surprised to see Tommy at the door. "Forgot my key," he said. "Forgot your birthday too." He pulled a bunch of roses from behind his back.

    "Oh, Tommy," I cried. "I love flowers!"

Don't ignore (忽略) the difference teenagers can make.

John Michael Thomas, 14, Florida

When John Michael Thomas decided to honor his friend and classmate Elizabeth Buckley, who died from cancer, he remembered how much she loved peacocks (孔雀).

He wanted to build a life-sized peacock fountain (喷泉) in Elizabeth's favorite park in the city. He thought it could be a place for people to relax and be inspired.

John Michael raised $52,000 to build the fountain.

Barrett England, 13, Utah

The wheels began to turn for Barrett England when he heard about Karma Bike shop, a place where young people can earn free bikes by reading and performing community (社区) service.

Barrett visited Karma's owner with his idea: He would collect and repair used bikes and donate them to the shop.

He expected to get about 10 donated bikes. In the end, Barrett received 39.

Zachary Blohm, 15, Wisconsin

The 25-year-old playground at an elementary school near Milwaukee, Wis. was so small that only 70 of its 575 students could play on it at a time.

That's when Zachary Blohm saved the day. He and some volunteers wanted to build a huge playground. To raise money, Zac planned T-shirt and bake sales, sold tickets and more. He held monthly money-raising events for more than a year. Overall, he collected $130,000 — enough to finish his project.

Jack Zimmerman, 16, New Jersey

For some people, finding a meal is as simple as opening the refrigerator. For more than 366,000 hungry kids in New Jersey, it's not that easy.

That fact didn't sit well with Jack Zimmerman, who organized a drive to lessen childhood hunger in his state. His goal: create 40,000 packaged meals that could be donated to those in need.

On game day, Jack and his volunteers started their work. After the final count, the team had packaged 47, 124 meals—well above Jack's goal.