CREATE TABLE table_name_76 (administrative_district VARCHAR(255), pre_1009_province VARCHAR(255), post_1009_province VARCHAR(255))
Which Administrative district has a Pre-1009 province of gwannae -do and a Post-1009 province of seohae -do?
    
SQL: SELECT administrative_district FROM table_name_76 WHERE pre_1009_province = "gwannae -do" AND post_1009_province = "seohae -do"