A、SELECT last_name, department_name FROM employees NATURAL JOIN departments;
B、SELECT last_name, department_name FROM employees JOIN departments ;
C、SELECT last_name, department_name FROM employees e JOIN departments d ON (e.department_id = d.department_id);
D、SELECT last_name, department_name FROM employees e RIGHT OUTER JOIN departments d ON (e.department_id = d.department_id);
E、SELECT last_name, department_name FROM employees FULL JOIN departments ON (e.department_id = d.department_id);
F、SELECT last_name, department_name FROM employees e LEFT OUTER JOIN departments d ON (e.department_id = d.department_id)