In this task, you're given a pair of sentences, sentence 1 and sentence 2. Your job is to determine if the two sentences clearly agree/disagree with each other, or if this can't be determined. Indicate your answer as yes or no respectively.
Q: Sentence 1: His serious business included organizing the first system of man-made levees to protect the city from the Mississippi. Sentence 2: The system of man-made levees took several years to build.
A:
no