Answer the following questions: 1- What are reasons for Studying Concepts of Programming Languages? 2- What are the main differences between Operational semantics, Axiomatic semantics, and Denotational semantics? 3- List 3 of the programming language domains. 4- Briefly describe the Implementation Methods in programming Languages 5- The diagram below includes errors. Draw circles on the errors and correct them. A parse tree for the simple statement: A=B*(A+C) 6- Is there any limit on the length of variables names forms in the Java language? 7- Explain the four primitive data types in general in all programming languages