读图，图中O点为地球表面昼半球的中心点，a为经线，b为纬线。据此回答下列各题。b纬线

     Last Saturday, our school organized a talent show to raise money for charity. It was a great success.
Students took an active part in it and we raised 20,000 yuan in all.
     After the show I interviewed three students. First, I talked with Liu Li. In the talent show, she danced
the ballet(芭蕾舞). "How long have you been dancing the ballet?" I asked. "For about six years." she
answered. "Why do you learn it?" "I think it's beautiful and I want to be a professional dancer when I
grow up."
    Next I had a talk with Zhao Qiang. He played a piece of Mozart's music. He played wonderfully. I
asked, "When did you start playing the piano?" "Um, I'm twelve now and I have been doing it since I
was five." he said. "Are you going to play the piano after you finish high school?" "Sure. My dream is to
be a pianist."
    Finally, I asked Chen Yun, an 11-year-old girl. She sang us some folk songs(民歌). Her voice is
very sweet. "Why are you interested in folk music?" I asked. "I admire Song Zuying and I want to be
a singer like her. I have been singing folk songs since five years ago. I hope I can hold a singing concert
in the future." she said.
根据短文内容，完成表格。