Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) Which three statements insert a row into the table? （）
- A INSERT INTO employees VALUES (NULL, 'John', 'smith');
- B INSERT INTO employees (first_name, last_name) VALUES ('John', 'smith');
- C INSERT INTO employees VALUES ('1000, 'John', 'smith');
- D INSERT INTO employees (first_name, last_name, employee_id) VALUES (1000, 'John', 'smith');
- E INSERT INTO employees (employee_id) VALUES (1000);
- F INSERT INTO employees ( employee_id, first_name, last_name, ) VALUES (1000, 'John','')