Absence is related to Black. Black is related to Oil. Oil is related to Salad. 
Testify is a synonym of Prove. Prove is related to Must. Must is related to Order. 
Absence <--RelatedTo--> Black <--RelatedTo--> Oil <--RelatedTo--> Salad 
Testify <--Synonym--> Prove <--RelatedTo--> Must <--RelatedTo--> Order 