Read this passage from President Barack Obama's 2009 speech "Address to America's Schoolchildren": That's why today I'm calling on each of you to set your own goals for your education — and do everything you can to meet them. Your goal can be something as simple as doing all your homework, paying attention in class, or spending some time each day reading a book. Maybe you'll decide to get involved in an extracurricular activity, or volunteer in your community. Maybe you'll decide to stand up for kids who are being teased or bullied because of who they are or how they look, because you believe, like I do, that all young people deserve a safe environment to study and learn. Maybe you'll decide to take better care of yourself so you can be more ready to learn. . . . But whatever you resolve to do, I want you to commit to it. I want you to really work at it. Why does the president use repetition in this passage?