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: An old man walked with a cane. He started to fall on the ice. A person looking out for him saved him. The man was so thankful. The man bought the person a drink.
 selected sentence: He started to fall on the ice.

An old man walked with a cane >Causes/Enables> An old man started to fall on the ice