When they first invented the clock how did they know what time it was to set it?

Why is ketchup sold by weight and mayonnaise sold by volume?

Why is 'do' pronounced 'dooo' while 'so' is pronounced 'sO' instead of 'sue'? Did the English language do this on purpose to make learning our language difficult for outsiders or what?

Why is it that on juice cartons they put the words 'Serve Ice Cold'? How else would you serve ice?

Why do some reports have a blank page with "This page is left blank intentionally" on it? It's not blank if you print that message on it Right?