多项选择题
A.SUM（start_date）
B.AVG（start_date）
C.COUNT（start_date）
D.AVG（start_date，end_date）
E.MIN（start_date）
F.MAXIMUM（start_date）
单项选择题 Examine this statement: SELECT student_id, gpa FROM student_grades WHERE gpa > &&value; You run the statement once, and when prompted you enter a value of 2.0. A report is produced. What happens when you run the statement a second time?（）
单项选择题 Evaluate the set of SQL statements: CREATE TABLE dept (deptno NUMBER(2), dname VARCHAR2(14), loc VARCHAR2(13)); ROLLBACK; DESCRIBE DEPT What is true about the set?（）
单项选择题 Examine the structure of the EMPLOYEES and DEPARTMENTS tables: EMPLOYEES EMPLOYEE_ID NUMBER DEPARTMENT_ID NUMBER MANAGER_ID NUMBER LAST_NAME VARCHAR2(25) DEPARTMENTS DEPARTMENT_ID NUMBER MANAGER_ID NUMBER DEPARTMENT_NAME VARCHAR2(35) LOCATION_ID NUMBER You want to create a report displaying employee last names, department names, and locations. Which query should you use?（）