阅读理解。 Do you have a mobile phone? Do you send text messages to your friends and family? Text messaging or 'texting' is becoming very popular. But, scientists have discovered that texting can give us problems with our hands. Be careful! Too Much texting can cause RSI (Repetitive Stain Injury) in our thumbs and wrists. We spoke to a doctor called Harriet Wilson, who treats many patients with RSI. She says if we spend more than 10-15 minutes texting each time, we could have problems in the future. Dr. Harjeet Deepa, who treats RSI patients, said that the youngest patient she had treated was a five-year-old girl. She had such bad RSI in her hands that she couldn't hold a pencil. As mobile phones develop, they are getting smaller with buttons closer together. Texting with a smaller phone, is worse than using a larger phone with bigger buttons. Using computers and playing video games can cause the same problem. So more and more people could find themselves with RSI. Many university students and teenagers have RSI. If we don't do anything about this, too many young people could grow up in terrible pain. (     )1. Too much texting can cause RSI. (     )2. If we spend five minutes texting each time, we could have problems in the future. (     )3. Dr. Harriet Wilson said the youngest patient she has treated was a five-year-old girl. (     )4. Mobile phones are getting smaller and the buttons are getting closer together. (     )5. Using computers and playing video games can't cause RSI.