Trouble is related to Circumstance. Circumstance is related to Condition. Condition is a synonym of Requirement. 
Blood is related to Gang. Gang is a synonym of Circle. Circle is a synonym of Curve. 
Trouble <--RelatedTo--> Circumstance <--RelatedTo--> Condition <--Synonym--> Requirement 
Blood <--RelatedTo--> Gang <--Synonym--> Circle <--Synonym--> Curve 