The chart in the PDF tile shows an E$-$R diagram.Each box in the diagram has been created as a table with the primary key $($PK$)$ and attributes $($data fields$)$ as shown in the diagram$\mathrm{.}1.$ For the five boxes without a primary key shown, select an appropriate primary key compatible with $3$NF$.$ That is$,$ the key should uniquely determine each record, only the key should uniquely determine each record, and there should be no transitive dependencies in the table$\mathrm{.}2.)$ Suppose that the field Staff Zip determines the two fields Staff City and Staff State. How would you split the Staff table into two tables following $3$N$?||3.$ For the Manager table, suppose that some of the fields track historical as well as current data.Manager. Performance is quarterly, Manager.CarAllowance is annual, and Manager Monthly bonus is monthly. How would you split the Manager table into a set of tables following $3$NF$?$