A．SELECT 姓名，性别,YEAR(DATE())-YEAR(出生日期) 年龄 FROM 职工 WHERE
年龄＜=40
B．SELECT 姓名，性别,YEAR(DATE())-YEAR(出生日期) 年龄 FROM 职工 WHERE
YEAR(出生日期)＜=40
C．SELECT 姓名，性别,YEAR(DATE())-YEAR(出生日期) 年龄 FROM 职工 WHERE
YEAR(DATE())-YEAR(出生日期)＜=40
D．SELECT 姓名，性别，年龄=YEAR(DATE())-YEAR(出生日期) FROM 职工 WHERE
YEAR(DATE())-YEAR(出生日期)＜=40