mysql数据中以班号Class和年龄(出生年月Sbirthday)从大到小的顺序查询student表中的全部记录 ()。
A.select class,Sbirthday from Student order by Class asc Sbirthday asc
B.select asasbithday from sudent order by Class des.Sbirthday desc
C.select cass,sbithday from Student order by Class asc, Sbirthday desc
D.select dasssbirthday from Student order by Cass desc Sbirthday asc