Misc: The chief food for more than half the people in the world is ____?

Questions

what are the two ends of a magnet called?

off of what countries coast do you find the great barrier reef?

what is the correct term for a screwdriver with a 'star shaped' head?

what is the first name of U2's lead singer?

If I was standing on the Canso Causeway, what country would I be in?