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: Mary was at her friend Ellen's house. All of a sudden, a huge animal ran in. Mary thought it was a pony! It was Ellen's dog, a Great Dane. Mary didn't know a dog could possibly be that large.
 selected sentence: Mary didn't know a dog could possibly be that large.

Mary never sees a great dane >Causes/Enables> Mary doesn't know dogs can be that large