In this task, you're given an article and an answer. Your task is to generate the question for the answer based on the given article.

Article: Most of us remember our teachers well. Three successful Americans talk about the teachers who encouraged them. Kevin Henkes is an excellent author and illustrator whose books include Lilly's Purple Plastic Purse, The Year of Billy Miller, and Kitten's First Full Moon, which won the Caldecott medal. "I grew up in the school days of silent hallways and desks in neat,evenrows. One day, our forth-grade teacher allowed the class to move the desks out of rows intogroups of four. It might seem like a small thing now, but it taught me that you could do things differently; you could think outside the box. That teacher helped me view my world differently. Good teachers can change lives." Katherine Applegate has won many awards for her books, including the Newbery Medal for The One and Only Ivan. She also created the Animorphs series with her husband, Michael Grant."My sixth-grade teacher in Michigan sensed that 1 wanted to write,so one day she sent me home to write about the word'blue'in as many ways as possible. Because of that,for the first time in my life, I thought of myself as someone with special skills as a writer, someone who was unique. My teacher's actions said'I see something special in you.'" In his role as U.S.Secretary of Education, Arne Duncan is in charge of the department that collects data and directs research on America's schools."My high school English teacher was amazing. She challenged us to express our ideas clearly in class and in our writing. There was no such thing as a bad question. She wanted to hear from us and encouraged us to speak up and express ourselves. She pulled things out of me that I didn't know I had inside. I think that is the genius of good teachers."
Answer: by asking her to write in various ways.
How did the teacher encourage Katherine Applegate?

Article: No one knows exactly when jazz was invented, or by whom. But it is said that it began in the early 1900s. Jazz was a new kind of music, for America and the world, and New Orleans was its birthplace. Who were the jazz pioneers? Most were blacks. This music was not written down, and at first only blacks played it. It was hard for white musicians to learn the new style. But soon they, too, were playing jazz. The popularity of this music spread. From New Orleans, it traveled up the Mississippi to Chicago, then to Kansas City and New York. By the 1920s, there were many jazz musicians, both black and white. Many of them were famous. One man was better than the rest. His name was Louis Armstrong. Louis Armstrong was a born musician. He was not only talented but also hard-working. He also had a good sense of humor and a big, good-natured smile. These personal qualities were valuable in his rise to fame. After he became famous, he traveled around the world. It seemed that everyone wanted to hear Louis play. But life was not always easy, especially at the beginning. Louis Armstrong was born in 1900 in New Orleans. His father never went to school and his mother could hardly read. When Louis was still a kid, his parents separated, and Louis lived with his mother. How hard their life was can readily be imagined. And yet Louis smiled through everything. He later wrote, "My whole life has been happiness. Life was there for me and I accepted it. Whatever happened has been beautiful to me. I love everybody."
Answer: His talent and hard work.
What made Louis Armstrong become the best jazz musician?

Article: A trip across the Pacific will guarantee you a different experience with a tipping culture you've never come across in China. In the US, giving a little extra money to service workers on top of your bill is a common practice. Though US national law requires that businesses pay workers at least $7.25 (45 yuan) per hour, employees receiving tips--often waiters and waitresses--are the exceptions. They usually only receive at least $2.13 an hour, and tips make up the difference. As theWall Street Journalput it, "The American system of tipping holds the promise of great rewards for waiting staff." So how should you tip if you are in the US. Normally you pay tips as a percentage of the bill. Offering an extra 15 percent of the bill to the waiter or waitress in a restaurant and to the delivery man or woman is customary and expected. You can offer more for great service and less for poor service. Yet there is an exception. For take-out food, you don't have to provide tips, though some people say that filling an order still requires work and time that deserve a little extra--but maybe a little less. Tips are not expected at fast food restaurants, cafes or ice cream shops either, though a tip jar might be right by the cash register . Don't feel _ to throw some money in, but also remember that it doesn't hurt. Those workers do not rely on tips. Other service workers also receive tips. For taxi drivers, 15 percent is the norm , more if they help with your bags. Hairdressers often receive about 15 percent of the bill. The same goes for spa therapists and tour guides. Today, you can even pay tips on a credit card. When receiving a copy of the bill to sign, you are free to fill in how much you'd like to tip. Though thinking about when to tip and how much you should tip causes a big headache for many Chinese people, it's important to bear in mind that as long as you show respect and use your reasoning, things will be just fine.
Answer: How to giving tips properly in the US.
What is the article mainly about?