Given the task definition and input, reply with output. 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.

Sentence1: Desi wanted her own aquarium very badly. Sentence2: She knew nothing about fish, but she began to research. Sentence3: When she felt she understood enough, she bought a fish tank. Sentence4: Her two little fish grew big and strong.
Soon she added more fish and bought a larger tank!