判断下列句子是否与短文相符。

    Mary is a little girl. She is only four. She is not at school. She doesn't know how to read or write. But her sister Joan is a schoolgirl. She is ten years old. She knows how to read and write.

    One day, Joan sees her little sister in the room. She is at the table. She has a pencil in her hand. She is writing." What are you writing, Mary?" She asks. "I'm writing a letter to my friend Rose."

    "But how can you? You don't know how to write," says her sister.

    "Well." says Mary, "It doesn't matter. Rose doesn't know how to read."