Question 23 is based on the passage you have just heard.

听力原文

    A question we often ask others and are also frequently asked by others is “What do you normally do after school or work?” Some commonplace answers are, “Well, I go to the gym.” “Um, I just go home and watch TV.” “I meet my friends for dinner.” or “I just go to bed because it’s so late and I’m tired.” Unlike any of these typical responses, I’m proud to say that I love to dance salsa after a long and tiring day of work.

    (22) Salsa is a kind of dancing that evolved in the mid-1970s in New York. (23) My dancing life began not because I wanted to do it, but because my mother was sick and tired of seeing me running around after school doing nothing. So she enrolled me into a ballet course when I was six. I fell in love with it instantly and continued with ballet dancing for about ten years. (24) Then, I left my native country of New Zealand to start my career as an English teacher, which eventually brought my dancing life to a halt. It wasn’t until I rediscovered salsa in a lovely studio while working in Asia that I renewed my passion for dancing. Since then, I have been trying to attend dancing classes twice a week after work. (25) It’s a great way for me to relieve stress and pressure and dance my way towards feeling energetic and happy again.

23. Why did the speaker’s mother enroll her in a ballet course?

解析：C。根据录音可知，作者开始跳舞不是因为自己想要跳舞，而是因为作者的妈妈不想看到作者在放学后无所事事，到处瞎跑。C项中的idling about是对录音中doing nothing, running around的同义替换，为正确答案。其他三项在录音中均未提及，故排除。