Best is related to Friend. you are likely to find Friend in/at/on Home. Cottage is a type of Home. Cottage can be used for Vacation. 
Reach is related to Dinner. you are likely to find Meat in/at/on Dinner. Meat is a synonym of Sum. 
Best <--RelatedTo--> Friend --AtLocation--> Home <--IsA-- Cottage --UsedFor--> Vacation 
Reach <--RelatedTo--> Dinner <--AtLocation-- Meat <--Synonym--> Sum 