CREATE TABLE table_name_68 (county VARCHAR2, listed VARCHAR2, construction_completed VARCHAR2)

In what county is the entry that has a Construction Completed date of 07/19/2000 and a Listed date of 09/21/1984 located?
SELECT county FROM table_name_68 WHERE listed = "09/21/1984" AND construction_completed = "07/19/2000"
SELECT "county" FROM "table_name_68" WHERE "07/19/2000" = "construction_completed" AND "09/21/1984" = "listed"