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: When the substitute walked into the class, she looked at us. She never bothered to say hi and asked us to take out our homework. She took it and decided to give us a packet. We didn't complete it since it covered material that we didn't cover. She ended up holding the class until all of us finished it.
 selected sentence: We didn't complete it since it covered material that we didn't cover.

The substitute gives us a packet >Causes/Enables> We don't complete the packet