you are likely to find Monster in/at/on Bed. Bed is related to River. Lot is a type of River. 
Production is related to Art. Poem is a type of Art. Poem can be used for Class. 
Monster --AtLocation--> Bed <--RelatedTo--> River <--IsA-- Lot 
Production <--RelatedTo--> Art <--IsA-- Poem --UsedFor--> Class 