# Question description 1. Look carefully at the definition of a graph. In one respect, graphs are more specific than trees. What is it? 2. What is the relationship between the sum of the degrees of all vertices and the number of edges of graph G = (V,E)? 3. What is the complexity of breadthFirstSearch()? 4. Show that a simple graph is connected if it has a spanning tree.

**Question description**

**1. **Look carefully at the definition of a graph. In one respect, graphs are more specific than trees. What is it?

**2. **What is the relationship between the sum of the degrees of all vertices and the number of edges of graph *G *= (*V,E*)?

**3. **What is the complexity of breadthFirstSearch()?

**4. **Show that a simple graph is connected if it has a spanning tree.