CREATE TABLE table_34570 ("Episode No." TEXT, "Episode Title" TEXT, "UK Broadcast Date" TEXT, "Presenter" TEXT, "Countries Visited" TEXT)

What is the UK broadcast date of the episode with Ben Okri as the presenter?
SELECT "UK Broadcast Date" FROM table_34570 WHERE "Presenter" = 'ben okri'
SELECT "UK Broadcast Date" FROM "table_34570" WHERE "Presenter" = 'ben okri'