Question 4: (7 Marks) Given a relation schema R(A,B,C,D,E, F) with F={ ABC, BC, C+BD, BD>E, E>D} 1- Give two different minimal covers of F 2- Determine all keys of R 3- Determine C and (CE) 4- Why R is not in 2NF? 5. Give a 2NF decomposition of R 6- Give a 3NF decomposition of R 7- Is your decomposition BCNF? If not give a BCNF decomposition. Question 5: (3 Marks) 1. Explain what is DDL. 2. What is it meant by Relational Algebra Language (RAL) is complete for the first order logic. 3. What is it meant by TRC is equivalent to Relational Algebra Language