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: There was a little boy who liked to collect rocks. He went to his favorite collecting place. He could not find any rocks. So he got a shovel and dug a three foot hole. It is too bad that his favorite place for rocks was mom's garden.
 selected sentence: He could not find any rocks.

The boy looks for rocks >Causes/Enables> The boy can't find any rocks