Mary is a little girl. She is only five years old. She does not go to school. She can't read or write. Her sister Cathy is a schoolgirl. She is ten. She can read and write well. Onc day, Cathy sees her little sister Mary in the room. She is at the table. There is a pencil in her hand. She is writing. "What are you writing, Mary?" she asks. "I'm writing to my friend Rose.""But how can you? You don't know how to write. You are only five.""Well," says Mary, "It doesn't matter. Rose can't read, either(也). She is five too."