Which of the following statements are true about the fundamentals of object-oriented programming (OOP)?

Options:

1. Abstract classes are general and may contain methods without any particular implementation
2. OOP improves debugging and testing as the object definition is contained in one place
3. OOP promotes code reuse
4. OOP incorporates the principles of procedural programming
5. Classes contain the definition for what objects are and what they can do
6. Polymorphism involves passing on characteristics to child classes
7. Objects are code representations of real-world items