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: Quentin is a senior engineering student. Sentence2: He recently tried building his own robot. Sentence3: Quentin spent months on the project, working on and off. Sentence4: His initial tests were last week.
Unfortunately, he still has a lot of work to do.