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: Tim had a dentist appointment at noon. He made sure to leave the house early so he would get there on time. On the way he got a flat tire. He had to cancel his appointment. A tow truck came and drove him home.
 selected sentence: On the way he got a flat tire.

Tim drives over Something sharp >Causes/Enables> Tim gets a flat tire