#### Answer

If the graph has exactly 2 odd vertices, then the graph has at least one Euler path but no Euler circuit.

#### Work Step by Step

An odd vertex is a vertex with a degree that is an odd number.
To determine if a graph has an Euler path, we need to determine the number of odd vertices in the graph. If the graph has 0 or 2 odd vertices, then the graph has at least one Euler path. If the graph has exactly 2 odd vertices, then the graph has at least one Euler path but no Euler circuit.