A group of fifteen-year-old students at Sunshine School are holding a charity sale to raise money to help their classmate Lisa. Lisa had cerebral palsy  when she was a baby. People who have cerebral palsy have trouble walking. Although Lisa has to use a wheelchair  to help her get around, she never gives up. And she is always ready to help others. "Lisa has the chance of standing up, but she needs an operation  which will cost lots of money." Lisa's doctor said. "I never thought that I could stand up one day. Actually the news is surprising for me. However, when I see my parents are worried about the cost of the operation, I am sad. I am used to my life. I don't mind if I can't stand up." Lisa said. "Now my classmates and some other kind people are helping me. I am really thankful. If I stood up one day, I could try my best to help more people." "While helping Lisa, we can also learn a lot. We have learned how to cook cookies  and how to sell them," Betty, one of Lisa's classmates said. "Now we know making money is not easy, so we won't waste money anymore." Alex, a boy in Lisa's class, told a reporter that they could raise about $100 every day. "We have raised about $2,100 so far. We hope we will raise more money for Lisa's operation." he said. What problem does Lisa have?
She can't speak. She can't stand up She has to stay in bed every day. She can't walk because of a traffic accident.