Answer:
go past the limits of
Step-by-step explanation:
The verb "to exceed" has two meanings: to be greater or superior in number or size than something else, or to go past or beyond the limits of something. The definition that best completes the sentence is the second one because if we were to replace "exceed" with "go past the limits of", the sentence would still make sense: If the river goes past the limits of its banks, it will flood the town.