1. Please refer to the ERD shown. Assume that the data that they represent has been properly normalized into 3NF, which means that all PK/FK relationships exist. Knowing, this, even without seeing any attributes, we are able to determine which of the following facts as true? (Indicate, with an X in the space provided, which are true) This is a one-to-one relationship Each table has a primary key The foreign key is carried on the PROFESSOR table It is possible for a PROFESSOR to teach only one CLASSEs The foreign key on PROFESSOR would be the primary key on CLASSes This is a many to many relationship The CLASSes table doesn't need a primary key It is possible for a PROFESSOR to not teach any CLASSes 2. What is used on Oracle to generate an automatically incremented sequential number as a primary key? 3. Answer true or false to this statement: It is possible to have a partial dependency in 1 NF without having a composite primary key