Concrete is related to Ground. you are likely to find Pit in/at/on Ground. Pit is a type of Remove. 
Preliminary is a synonym of Preparation. Preparation is related to Cook. Cook is related to Person. Person is related to Physician. 
Concrete <--RelatedTo--> Ground <--AtLocation-- Pit --IsA--> Remove 
Preliminary <--Synonym--> Preparation <--RelatedTo--> Cook <--RelatedTo--> Person <--RelatedTo--> Physician 