Yes.
No, MS-DOS does not support multi-threading (or multi-processing either).
Multi-threading is not part of the language.
Client/server programs typically employ multi-threading where the primary thread handles the server side of things while one or more threads handle the client side.
Some topics under Advanced Java are: a. Exception Handling b. Threading/Multi-Threading c. Remote Method Invocation d. Serialization e. etc
Multi-threading in c sharp is a system with different tutorial. Like: interaction between threads, producer, using thread pool and using mutex objects.
No. C++ is an extension of C. By the time you learn C++, you have learned C.
Not possible.
Sure.
No.
Not much. Examples, that are possible in C only: char str3[3] = "ABC"; int new;
C++ is not a command oriented language, it is a multi-paradigm language because it employs functional and object-oriented approaches to programming.
No. There can only be one main method, however you can declare new methods, and call them from the main method. Or you can use multi-threading, to simulate having multiple main methods.