Composite primary keys are particularly useful as identifiers of composite entities, where each primary key combination is allowed only once in the relationship.

Give an example of a case where a two-way handshake to establish a connection could leave one side of the connection live while the other side does not believe there is a connection.

1)consider the following code snippet: #ifndef book_h#define book_hconst double max_cost = 1000.0; class book{public: book(); book(double new_cost); void set_cost(double new_cost); double get_cost() const; private: double cost; }; double calculate_terms(book bk); #endifwhich of the following is correct? a)the header file is correct as given.b)the definition of max_cost should be removed since header files should not contain constants.c)the definition of book should be removed since header files should not contain class definitions.d)the body of the calculate_terms function should be added to the header file.

In cell h5 enter a formula that will calculate the percentage of attendees that went to the altamonte springs job fair in 2018.