A.select name,birth_city from worker where birth_city< >""B.select name,birth_city from worker where birth_city IS NOT NULLC.select name,birth_city from worker where birth_city!=""D.select name,birth_city from worker where birth_city=NOT_NULL
A.select name from list where status< >"正常"B.select name from list where status="请假,无故不参加,退赛"C.select name from list where status!="正常"D.A和C都正确
A.select name from employees where title="manager",title="senior_manager")B.select name from employees where title="manager"AND title="senior_manager"C.select name from employees where NOT title="manager"&title="senior_manager"D.select name from employees where title NOT IN ("manager","senior_manager")