100:00:23,007 --> 00:00:27,956In Cairo, a muezzin callsfaithful Muslims to prayer.200:00:34,727 --> 00:00:39,084It's the same call that soundsfive times a day, every day,300:00:39,287 --> 00:00:41,562in cities across the world.400:00:47,527 --> 00:00:50,917Nearly a quarter of the peopleon earth respond to it,500:01:05,567 --> 00:01:09,446'God is most great'