Describe three uses of the tree structure as a way of organizing information that you are familiar with. Some aspect of each of the following can be modeled with a graph structure. Describe, in each case, what the nodes would represent and what the edges would represent. Travel routes available through an airline Countries and their borders A collection of research articles about data structures Actors (research the "six degrees of Kevin Bacon") The computers at a university The Web What is an alias? Show an example of how it is created by a Java program. Explain the dangers of aliases. Assume that date1 and date2 are objects of class incDate as defined in Section 1.4. What would be the output of the following code? Date1 = new IncDate(5, 5, 2000): date2 = date1: System.out.println(date1): System.out.println(date2): date1.increment(): System.out.println(date1): System.out.println(date2): What is garbage? Show an example of how it is created by a Java program. Assume that date1 and date2 are objects of class IncDate as defined in Section 1.4. What would be the output of the following code? Date1 = new IncDate(5, 5, 2000): date2 = new incdate (5, 5, 2000)