Grass is related to Weekly. Weekly is related to Day. Day is related to Common. Common is related to Law. 
Body is related to Physics. Physics is related to Chemistry. Chemistry is related to History. 
Grass <--RelatedTo--> Weekly <--RelatedTo--> Day <--RelatedTo--> Common <--RelatedTo--> Law 
Body <--RelatedTo--> Physics <--RelatedTo--> Chemistry <--RelatedTo--> History 