What is meant by an opaque export from a module? What are private types in Ada? Explain the significance of this parameter in object-oriented languages. How do Java and C# make do without explicit...

What is meant by an opaque export from a module? What are private types in Ada? Explain the significance of this parameter in object-oriented languages. How do Java and C# make do without explicit class headers? Explain the distinctions among private, protected, and public class members in C++.