（多选题）Examine the structure of

题目描述

AINSERT INTO employees VALUES ( NULL, 'John', 'Smith');

BINSERT INTO employees( first_name, last_name) VALUES( 'John', 'Smith');

CINSERT INTO employees VALUES ( '1000', 'John', NULL);

DINSERT INTO employees (first_name, last_name, employee_id) VALUES ( 1000, 'John', 'Smith');

EINSERT INTO employees (employee_id) VALUES (1000);

FINSERT INTO employees (employee_id, first_name, last_name) VALUES ( 1000, 'John', ' ');