Definition: In this task, you will be given a short story. One sentence from the story is chosen. Consider the events that happen before that sentence, or are likely to have happened before it. Does any of them directly cause it, or simply make it possible? You should write your answer in the form " A >causes/enables> B". Try to use phrases and sentences from the story to compose your answer when possible.
Input: story: Mattie could not wait to get her very first library card. As soon as she ran into the library, the librarian gave her first card Mattie ran up and down the library aisles to find the perfect books. It must have taken hours for Mattie to decide on what she wanted. By the time she walked out the door, she had 10 books in her bag.
 selected sentence: By the time she walked out the door, she had 10 books in her bag.

Mattie goes to the library >Causes/Enables> Mattie gets books