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 was nervous about his first race today. He had practiced with his track team for weeks now. He lined up with the other runners at the start line. As soon as the gun went off, Tim sprinted down the track. He ended up winning first in his heat!
 selected sentence: Tim was nervous about his first race today.

Tim joins the track team >Causes/Enables> He is nervous about the race