题目5单选题
有关系模型Students(学号,姓名,性别,出生年月),要统计学生的人数和平均年龄应使用的语句是A. SELECT COUNT() AS 人数,AVG(YEAR(出生年 月))AS 平均年龄 FROM StudentsB. SELECT COUNT(*) AS 人数,AVG(YEAR(出生年月))AS平均年龄FROM StudentsC. SELECT COUNT(*) AS 人数,AVG(YEAR(DATE ())-YEAR(出生年月))AS 平均年龄 FROM StudentsD. SELECT COUNT ( ) AS 人数,AVG(YEAR( DATE ())-YEAR(出生年月))AS 平均年龄 FROM Students