What can technology do to make your world better?Three young people are starting new businesses to answer that question.

Mateusz Mach

    Eighteen-year-old Mateusz Mach was the youngest person in Poland to receive money from investors to expand his company.He started Five,a mobile messaging application,or app,for deaf people.The app lets deaf people create their own hand signs to communicate with friends.The app now has more than 10,000 deaf users.And Mach thinks there will be about 150,000 more deaf users in the U.S. next year.There are many different sign languages in various parts of the world.Mach will be working with the United Nations in New York.He says,"I love to create.And I think that the creation of things will be my passion to the end of my life."

    William Zhou

    William Zhou is the co-founder and leader of Chalk.com.The education software company helps teachers from the kindergarten level t0 12th grade,or the end of secondary school.Zhou was born in Beijing,China,grew up in the Canadian city of Vancouver and founded his first company when he was still in high school.Zhou sold the company when he was studying computer science at Canada's University of Waterloo.But he strongly wanted to make a change in education,From his dorm room,Zhou created Chalk.It is a group of programs that supports individual teaching and learning.Based in Canada,Chalk is now used in 20,000 schools by more than 100,000 users worldwide. Zhou says building startups is a difficult process because it could last years."It's only worth it if you find something you truly care about—something you're passionate about.Otherwise,you may just end up crashing."

    George Mtemaharji

    George Mtemahanji was born in the African country of Tanzania and moved with his family to Italy in 2002, where he attended the Technical Institute of Alfredo Ferrari in Maranello.There he learned about renewable energy and began thinking that solar energy would be easier to use in Africa than in Europe.After graduation,he returned to Tanzania in 2014 to start his own solar energy company—Sun Sweet Solar—in partnership with his friend Manuel Rolando.He explains that he could not understand why,in a place with bright sunshine,"more than 90 percent of people had no access to electricity.So when I returned to Italy I spoke with Manuel on the huge electricity demand in Tanzania and to the possibility to open a business there."Sun Sweet Solar found early success in rural areas of Tanzania.Since then,the company has been expanding.He hopes to create jobs and help build his country in the process.He understands the process will take time."But I think we are on the right path."

    Elizabeth Freeman was born about 1742 to African American parents who were slaves. At the age of six months she was acquired, along with her sister, by John Ashley, a wealthy Massachusetts slaveholders. She became known as “Mumbet” or “Mum Bett.”

    For nearly 30 years Mumbet served the Ashley family. One day, Ashley's wife tried to strike Mumbet's sister with a spade. Mumbet protected her sister and took the blow instead. Furious, she left the house and refused to come back. When the Ashleys tried to make her return, Mumbet consulted a lawyer, Theodore Sedgewick. With his help, Mumbet sued(起诉) for her freedom.

While serving the Ashleys, Mumbet had listened to many discussions of the new Massachusetts constitution. If the constitution said that all people were free and equal, then she thought it should apply to her. Eventually, Mumbet won her freedom—- the first slave in Massachusetts to do so under the new constitution.

    Strangely enough, after the trial, the Ashleys asked Mumbet to come back and work for them as a paid employee. She declined and instead went to work for Segdewick. Mumbet died in 1829, but her legacy lived on in her many descendants(后裔). One of her great-grandchildren was W.E.B. Du Bois, one of the founder of the NAACP, and an important writer and spokesperson for African American civil rights.

    Mumbet's tombstone still stands in the Massachusetts cemetery where she was buried. It reads, in part: “She was born a slave and remained a slave and remained a slave for nearly thirty years. She could neither read nor write, yet in her own sphere she had no superior or equal.”

    As a young girl growing up in the 1930s, I always wanted to fly a plane, but back then it was almost unheard of for a woman to do that. I got a taste of that dream in 2001, when my husband arranged for me to ride in a hot air balloon for my birthday. But the experience turned out to be very dull. Around that time, I told my husband that I wanted to skydive. So when our retirement community announced that they were having an essay competition and the topic was an experience of a lifetime that you wanted to have, I decided to write about my dream.

    In the essay, I wrote about my desire to skydive, stating George Brush Sr. did age 80. Why not me? I was just 84 and in pretty good health. A year went by and I heard nothing. But then at a community party in late April 2009, they announced that l was one of the winners. I just couldn't believe it. Inspired by this, I decided to realize my dream, even though some of my family members and my doctor were against it.

    One June 11, 2009, nearly 40 of my family and friends gathered in the area close to where I would land while I headed up in the airplane. My instructor, Jay, guided me through the experience. The plane was the noisiest one I had ever been in, but I wasn't frightened－I was really just looking forward to the experience. When we reached 13,000 feet, Jay instructed me to throw myself out of the plane. When we first hit the air, the wind was so strong that I could hardly breathe. For a second I thought, “What have I gotten myself into?” But then everything got calmer. We were in a free fall for about a minute before Jay opened the parachute （降落伞）, then we just floated downward for about five minutes. Being up in the clouds and looking at the view below was unlike anything I have ever felt－much better than the hot air balloon. I was just enjoying it.

    Skydiving was really one of the greatest experiences of my life. I hope other people will look at me and realize that you don't stop living just because you are 84 years old. If there's something you want to experience, look into it. If it's something that is possible, make it happen.

    Reading can be a social activity. Think of the people who belong to book groups. They choose books to read and then meet to discuss them. Now, the website BookCrossing.com turns the page on the traditional idea of a book group.

    Members go on the site and register the books they own and would like to share. BookCrossing provides an ID number to stick inside the book. Then the person leaves it in a public place, hoping that the book will have an adventure, traveling far and wide with each new reader who finds it.

    Bruce Pederson, the managing director of BookCrossing, says “The two things that change your life are the people you meet and books you read. BookCrossing combines both.”

    Members leave books on park benches and buses, in train stations and coffee shops. Whoever finds their book will go to the site and record where they found it.

    People who find a book can also leave a journal entry describing what they thought of it. E-mails are then sent to the BookCrossers to keep them updated about where their books have been found. Bruce Pederson says the idea is for people not to be selfish by keeping a book to gather dust on a shelf at home.

    BookCrossing is part of a trend among people who want to get back the “real” and not the virtual(虚拟). The site now has more than one million members in more than one hundred thirty-five countries.

    “Helicopter parent” may not sound pleasant, but given the chance, most parents would probably prefer a vehicle to zoom (快速移动)little ones between school, football practice and piano lessons. Getting children where they need to go is a huge task and expense, especially in homes where both parents work. Hailing rides (专车服务)through firms like Uber and Lyft has made life more convenient for adults. But drivers are not supposed to pick up kids who travels without an adult aside (although some are known to bend the rules).

    Children represent a fresh-faced opportunity. Ride-hailing for kids could be a market worth at least $50bn in America, hopes Ritu Narayan, the founder of Zum, one of the startups in want of the prize. These services are similar to Uber's, except they allow parents to schedule rides for their children in advance. Children are given a code word to ensure they find the right driver, and parent sreceive warnings about the pick-up and ride, including the car's speed. These services promise more careful background checks finger printing and training than typical ride-hailing companies.

    Annette Yolas, who works in sales at AT&T, says that she spends around $200 a month on Hop Skip Drive, a service that operates in several markets in California, for her three kids to get to the school bus on time and to ballet practice. She says it has been a “life-saver” by allowing her to work longer hours. Meanwhile, kids avoid the embarrassment of a relative pulling up at school. But ride-hailing firms for kids may end up like the children in Neverland, and never fully grown. They face several challenges. One is finding enough drivers. All users need rides during the same limited set of hours: before and after school, which makes it hard to offer drivers enough work. It can also be challenging to persuade parents, who have drilled it into children never to get in a stranger's car.

    And while ride-sharing companies can annoy adult passengers by cancelling or being late, such behavior can be a disaster when children are involved. Shuddle, an early entrant in the taxis-for-kids business, which shut down in 2016, had only two out of five stars on Yelp (点网站)for that reason， and lots of negative reviews from parents. It had made money on rides mainly by raising prices ever higher.

    Shuddle's failure has not discouraged Uber itself, which is expected soon to launch a pilot programme for teenagers under 18. Parents may be happier to use services they are familiar with. But Uber's entrance is likely to add to the struggle of child-focused ride-hailing businesses as they compete for customers and new funds.

    Planning a visit to the UK? Here we help with ways to cut your costs.

    AVOID BIG EVENTS Big sporting events, concerts and exhibitions can increase the cost of accommodation and make it harder to find a room. A standard double room at the Thistle Brighton on the final Friday of the Brighton Comedy Festival (19 Oct.) cost £169.15 at Booking.com. A week later, the same room cost £l18.15.

    If you can be flexible and want to know dates to avoid-or you're looking for a big event to pass your time—check out sites such as Whatsonwhen.com, which allow you to search for events in the UK by city, date and category.

    STAY AWAY FROM THE STATION If traveling to your destination by train, you may want to find a good base close to the station, but you could end up paying more for the sake of convenience at the start of your holiday.

    Don't be too choosy about the part of town you stay in. Booking two months in advance, the cheapest room at Travelodge's Central Euston hotel in London for Saturday 22 September was £95.95. A room just a tube journey away at its Covent Garden hotel was £75.75. And at Farringdon, a double room cost just £62.95.

    GET ON A BIKE London's 'Boris bikes' have attracted the most attention but other cities also have similar programmes that let you rent a bicycle and explore at your own pace, saving you on public transport or car parking costs.

    Among the smaller cities with their own programmes are Newcastle (casual members pay around £1.50 for two hours) and Cardiff (free for up to 30 minutes, or £5 per day).