Task: Question Answering
Input (English): She had a little tape recorder , and turned it on to play the same music as before . Though I was still dizzy , I began to dance again , only slightly more aware of how goofy I looked because I could see my shadow dancing with me on the sand . The song went on and on , and I started getting tired . I said , " It's like the Red Shoes , isn't it ? " 
Question: What's a possible reason the writer started getting tired ?
Output (English): Because dancing is a physical activity .