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: The Omaha zoo was getting new elephants in their zoo. The family drove one hour to go to see the elephants. Once they got their they had to walk to the back of the zoo. One of the elephants was hiding behind the feeding shed. The other four elephants were out and enjoying the sun and visitors.
 selected sentence: Once they got their they had to walk to the back of the zoo.

The elephants are at the back of the zoo >Causes/Enables> They had to walk to the back of the zoo