招标人和中标人不应当自中标通知书发出之日起三十日内，按照招标文件和中标人的投标文件订立书面合同。
Examine the structure of the EMPLOYEES table: EMPLOYEE_ID NUMBER NOT NULL EMP_NAME VARCHAR2(30) JOB_ID VARCHAR2(20) SAL NUMBER MGR_ID NUMBER DEPARTMENT_ID NUMBER You want to create a SQL script file that contains an INSERT statement. When the script is run, the INSERT statement should insert a row with the specified values into the EMPLOYEES table. The INSERT statement should pass values to the table columns as specified below: EMPLOYEE_ID: Next value from the sequence EMP_ID_SEQEMP_NAME and JOB_ID: As specified by the user during run time, through substitution variables SAL: 2000 MGR_ID: No value DEPARTMENT_ID: Supplied by the user during run time through substitution variable. The INSERT statement should fail if the user supplies a value other than 20 or 50. Which INSERT statement meets the above requirements?（） INSERT INTO employees VALUES (emp_id_seq.NEXTVAL, &ename','&jobid', 2000, NULL, &did);。 INSERT INTO employees VALUES (emp_id_seq.NEXTVAL, '&ename', '&jobid', 2000, NULL, &did IN (20,50));。 INSERT INTO (SELECT * FROM employees WHERE department_id IN (20,50)) VALUES (emp_id_seq.NEXTVAL, &ename','&jobid', 2000, NULL, &did);。 INSERT INTO (SELECT * FROM employees WHERE department_id IN (20,50) WITH CHECK OPTION) VALUES (emp_id_seq.NEXTVAL, &ename','&jobid', 2000, NULL, &did);。 INSERT INTO (SELECT * FROM employees WHERE (department_id = 20 AND department_id = 50) WITH CHECK OPTION ) VALUES (emp_id_seq.NEXTVAL, &ename','&jobid', 2000, NULL, &did)。
简述如何有效利用幼儿园经费。
某男，不慎触电后倒地。脱离电源后，轻摇并呼唤患者，不见其反应。判断该患者心脏骤停的快捷方法是（） 听心音。 触颈动脉搏动。 观察瞳孔反映。 观察胸廓起伏。 测量血压。
Which two statements about bigfile tablespaces are true？ （） The bigfile tablespace have only one data file.。 The segment space management is automatic.。 The extent management is dictionary managed.。 The database can have only one bigfile tablespace.。 The bigfile tablespace can be converted to a smallfile tablespace.。
In which scenario will you use the Flashback Transaction Query feature？（）
