Grape is related to Skin. Skin is related to Forehead. Forehead is related to Hat. 
Back is related to Area. Pit is a type of Area. you are likely to find Pit in/at/on Backyard. 
Grape <--RelatedTo--> Skin <--RelatedTo--> Forehead <--RelatedTo--> Hat 
Back <--RelatedTo--> Area <--IsA-- Pit --AtLocation--> Backyard 