CREATE TABLE table_33776 ("Race Name" CLOB, "Circuit" CLOB, "City/Location" CLOB, "Date" CLOB, "Pole position" CLOB, "Fastest lap" CLOB, "Winning driver" CLOB, "Winning team" CLOB, "Report" CLOB)

What circut has an unknown fastest lap on July 19?
SELECT "Circuit" FROM table_33776 WHERE "Fastest lap" = 'unknown' AND "Date" = 'july 19'
SELECT "Circuit" FROM "table_33776" WHERE "Date" = 'july 19' AND "Fastest lap" = 'unknown'