Fork is a type of Tool. Pick is a type of Tool. 
Candle is related to Lighting. you are likely to find Lighting in/at/on Office. Office is related to Water. Water is related to Drain. 
Fork --IsA--> Tool <--IsA-- Pick 
Candle <--RelatedTo--> Lighting --AtLocation--> Office <--RelatedTo--> Water <--RelatedTo--> Drain 