Detailed Instructions: In this task, you're given a four sentences of story written in natural language. Your job is to complete end part of the story by predicting appropriate last sentence which is coherent with the given sentences.
Q: Sentence1: Bret decided to bake his own bread. Sentence2: He mixed the dough carefully. Sentence3: But when he pulled the bread out of the oven, he frowned. Sentence4: The bread had not risen!
A:
Bret realized he had forgotten the yeast!