某人之所以始终没有离开所在的工作单位，是因为：（)。A．他和单位签了协议，离开会有很大损失B．他对现

A．

B．

C．

D．

A.

B.

C.

D.

E.

A．

B．

C．

D．

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‘, NULL);

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‘, ‘ ‘);

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‘,‘‘);

A．

B．

C．

D．

A. You get an error because of a primary key violation.

B. The data and structure of the EMPLOYEES table are deleted.

C. The data in the EMPLOYEES table is deleted but not the structure.

D. You get an error because the statement is not syntactically correct.

A．

B．

C．

D．