1. True or False. [5 points each] (a)Most of the usual programming languages in use, including C++, are context-free. (b) Every context-free language that does not contain the empty string is generated by a Chom sky Normal Form grammar (c) Every subset of a regular set of integers is regular. A language L is context-free if and only there is some PDA that accepts L (e) A language L is context-free if and only there is some DPDA that accepts LS. _-- The intersection of any two context-free languages is context-free