# Can be a graph strongly connected but with undirected edges?

I'm studying graph theory and I'm facing the following question:

What happens when you have a connected graph with directed and undirected edges? Is it strongly connected or not?

With connected graph I'm saying that despite the 2 vertices of the graph you select, you can always find a path between them.

I was looking for the definition of strongly connected graph but I couldn't find if it is required that ALL the edges should be directed or not.

My thoughts are that if it's connected and you have at least one directed edge, then it is strongly connected, but I want to know if this is correct or not.

I reached to this conclusion because in the book I'm studying (Ralph Grimaldi - Discrete and Combinatorial Mathematics) when it defines what is a strongly directed graph, it show this graph:

And that's what I'm talking about, there are 4 directed edges and 1 undirected edge and the book call it a strongly connected graph.

Also and if this is true, then...

Do you have a directed graph when you have at least one directed edge on it or again... ALL the edges should be directed to call it a "Directed Graph"?