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: Tom wanted an apple from his apple tree. There was a beautiful one right at the top of the tree. He tried to climb the tree but couldn't reach the apple. He found a long stick that he used to knock it down. The apple fell and hit him on the head.
 selected sentence: He tried to climb the tree but couldn't reach the apple.

Tom climbs a tree >Causes/Enables> Tom can't reach the apple