Can you please help me out with question number 9?

I would be really thankful if you could help me out with the details. I am really confused about this assignment. And please don't copy other answers to here.

The JAVA 1.5 programming language specification, contains 52 reserved words. Is it possible to write a C-program to determine if a source file contains only acceptable reserved words, valid identifiers, acceptable numeric or string literals, and accepted punctuation? Why or why not? (Assume there are an infinite number of valid identifiers and numeric or string literals.) 9. Is the following language regular? Prove your answer. a) The set of all strings that do not have two consecutive a's. Yes. matores regular expression in specitic search pattern What is the regular express vem? b) L={anbp:np=2}