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: Billy asked his mom who Superman was. Instead of telling Billy, she decided to show him. She brought Billy down to the basement where dad was working. She then asked the dad what Superman looks like. The dad flexed his muscles and Billy laughed and laughed!
 selected sentence: The dad flexed his muscles and Billy laughed and laughed!

The dad flexes his muscles >Causes/Enables> Billy laughs