In the past, going to a piano teacher was the only way to learn how to play the piano. You could have one lesson a week. If you didn’t have private(个人的) lessons, you could still learn piano, but you would have to learn it by yourself. This was easy for some, but very difficult for most. However, with technology as it is today, there is at last another way that you can take piano lessons. You can take an online course.
An online course can save you lots of money. If a private lesson costs 30 or 40 dollars per week, just think about how quickly that adds up. You can take a complete online course in piano by spending a small part of the money that you would pay for taking weeks of private lessons. Also, private lessons are only usually one hour per week. If you have questions during the rest of the week, or if you forget something that your teacher said, you will have to wait for your next lesson to continue your learning. However, online piano courses are quite different.
With an online piano course, you can work at your own pace(进度). You can also take as many lessons per week as you’d want, or go back and listen to your last lesson if you have forgotten anything. Most adults who want to learn how to play the piano enjoy being able to go back and listen to lessons they watched before. It can give you a good idea of what you were doing right, what you were doing wrong, and what you should be doing before the next lesson.
Of course, if you need someone to sit beside you and give you instant feedback(及时反馈) while you are playing, you are not suggested to choose an online course. But most adult learners think they can get their own type of feedback by watching the course again and again.
       is not mentioned in the passage to learn to play the piano.
A.Going to a piano teacher        B. Asking experts for information   C. Teaching oneself
Going to a piano teacher is much more        than having an online piano course.
A. expensive                   B. convenient                  C. interesting
If you choose an online piano course, you can          .
A. ask questions whenever you want          
B. watch the lessons whenever you’d like  
C. get some advice while you are playing the piano.
Most adults like to go back and listen to the lessons again because         .
A. they needn’t spend any extra money          
B. they can ask some questions   
C. they can know what they were doing right, what they were doing wrong
How many advantages of an online piano course have been introduced in the passage?
A. 2                           B. 3                         C. 4