Think of some of your favorite singers. When you listen, they can make you happy or sad, peaceful or angry. They can make you relax or want to get up and dance. Gifted singers have the power to affect us in many ways -- emotionally, physically and mentally.  But becoming a great singer isn't as easy as listening to one. It takes practice, devotion and strong lungs! Just ask the well-known American opera star Carol Vaness.  At the Metropolitan Opera in prefix = st1 /New York Citywhere she often sings, Carol's voice must be loud enough to be heard by four thousand people. It must reach every person in the theater, without a microphone, even when she's singing softly. The reason Carol can project her voice that far is the way she breathes. "When you breathe, it's like a swimmer taking a deep breath before going underwater," Carol explains. "You have to take a lot of air into your lungs." According to Carol, the main difference between pop singing and opera is "how you breathe, how much air you take in, and how you control it coming out. Regular singing is more like speaking, and it's a lot softer. When I sing for children, they're often surprised by how the vibrations strike their ears -- like waves on a beach, " Carol says. "In opera, the air doesn't just go out of your mouth -- it vibrates in your chest, the way a guitar vibrates when it's played. " Ever since she started piano lessons at the age of ten, Carol has loved music. As she got older, she decided to become a music teacher. When she went to college, she took singing lessons as part of her studies. Her voice teacher discovered that nineteen-year-old Carol had an exceptionally beautiful soprano voice - the highest singing voice for women.  Carol decided to make opera her goal, not only because she loved to sing but also because she loved the drama. Opera is a play in which the characters sing the words instead of speaking them. The stories of opera can be tragic or comical. They can be personal stories about two people falling in love or grand stories about kings and queens who lived long ago. As the characters in an opera sing, the emotions expressed by words and music come to life.  Today, Carol performs throughout the United Statesand Europe and she has song for almost twenty years. But she has never forgotten where she started singing in the first palace. "Put your heart into your singing and enjoy it," says Carol, "because singing is a great joy. That's why I sing. In fact, that's why everybody sings. " From the passage you can conclude all the following EXCEPT that   _  .
Carol once learned to play the piano Carol worked as a music teacher Carol has been singing opera for 20 years or so Carol is popular with Americans and Europeans