Bit is a type of Fragment. Bit is related to Leaf. Leaf is related to Paper. Paper is related to Flexible. 
you are likely to find Tower in/at/on City. you are likely to find Hospital in/at/on City. 
Fragment <--IsA-- Bit <--RelatedTo--> Leaf <--RelatedTo--> Paper <--RelatedTo--> Flexible 
Tower --AtLocation--> City <--AtLocation-- Hospital 