Mary is twenty-three years old. She is a nurse at a big hospital. She is very kind, and all of her patients like her very much. One day she was out shopping when she saw an old woman waiting to cross a busy street. Mary wanted to cross the street, too, so she went over to help the woman cross. When Mary was near her, she shouted happily, "Mrs Herman! You were my patient last year." "Oh, thank you very much, Mary," Mrs Herman said, and stepped forward. "No, no, Mrs Herman," Mary said quickly, "the light's still red.""Oh," Mrs Herman answered as she stepped back. "I can easily cross the street alone when the light's green." Mary  _   before she met her in the street.
knew Mrs Herman didn't know Mrs Herman lived with Mrs Herman didn't see Mrs Herman