[单选] Which statement most accurately describes the implementation of a SQL Access Advisor recommendation？（）  

Which two statements are true regarding working with dates?（） The default internal storage of dates is in the numeric format 。 The default internal storage of dates is in the character format 。 The RR date format automatically calculates the century from the SYSDATE function and does not allow the user to enter the century 。 The RR date format automatically calculates the century from the SYSDATE function but allows the user to enter the century if required。 在流动资产评估中，对（）的评估实际上就是清查和确认其实有数额。 库存现金。 银行存款。 应收账款。 库存商品。 The DB_BLOCK_CHECKING initialization parameter is set to OFF.Which block checking would be performed?（） The Oracle database will perform block checking for the index blocks only。 The Oracle database will not perform block checking for any of the data blocks。 The Oracle database will perform block checking for the default permanent tablespace only。 The Oracle database will perform block checking for the data blocks in all user tablespaces。 The Oracle database will perform block checking for the data blocks in the SYSTEM tablespace only。 Examine the structure of the EMPLOYEES and NEW_EMPLOYEES tables: EMPLOYEES EMPLOYEE_ID NUMBER Primary Key FIRST_NAME VARCHAR2(25) LAST_NAME VARCHAR2(25) HIRE_DATE DATE NEW_EMPLOYEES EMPLOYEE_ID NUMBER Primary Key NAME VARCHAR2 (60) Which DELETE statement is valid?（） DELETE FROM employees WHERE employee_id = (SELECT employee_id FROM employees);。 DELETE * FROM employees WHERE employee_id = (SELECT employee_id FROM new_ employees);。 DELETE FROM employees WHERE employee_id IN (SELECT employee_id FROM new_employees WHERE name = 'carrey');。 DELETE * FROM employees WHERE employee_id IN (SELECT employee_id FROM new_employees WHERE name = 'carrey')。 按施工合同约定由双方提交的施工图纸应经监理机构审批后方可实施。 Which statement most accurately describes the implementation of a SQL Access Advisor recommendation？（）