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: Amy decided to open the curtains and let light into the house. She pulled back one of the curtains on her bedroom window. The nail holding the curtain rod fell, the curtains on the floor. Amy looked and looked, but was unable to locate the nail. Amy decided to leave the curtains down and enjoy the sun.
 selected sentence: Amy looked and looked, but was unable to locate the nail.

Amy looks for the nail >Causes/Enables> She is unable to locate the nail