A.1 B.2 C.25 D.0
A.DATE B.SYSDATE C.DATETIME D.CURRENTDATE
A.SELECT SYSDATE + 600 / 24 FROM 雇員; B.SELECT ROUND(聘用日期, DAY) FROM 雇員; C.SELECT (SYSDATE - 聘用日期) / 7 FROM 雇員; D.SELECT SYSDATE - 7 FROM 雇員;