.png" alt=""> <p>Hey!  That looks like the US!  You can see regional airports and get some sense of the overall connectivity.</p>
         <h2>Connected components<a name="21"></a></h2>
         <p>The connected components of a network determine which parts of the network are reachable from other parts.  One of your first
            questions about any network should generally be: is it connected?
         </p>
         <p>There are two types of connected components: components and strongly connected compo