Define the SOLID principles of object-oriented design (Single Responsibility, Open/Closed, Liskov Substitution, Interface Segregation, Dependency Inversion) and provide a practical example of how they can be applied.

The technique of packaging an objects attributes into a cohesive unit that can be used as an undivided entity is ____________. a. inheritance b. encapsulation c. polymorphism d. interfacing

Using a graphics program, develop an entity-relationship diagram for a database application for an Internet bookstore where students buy textbooks from a salesperson and receive invoices for their purchases. Use Figure 5.5 as a guide.