Rank is related to Smell. Smell is related to Test. Test is related to Questionnaire. 
Sudden is related to Fast. Fast is related to Fall. Fall is related to Airplane. Airplane is related to Arrive. 
Rank <--RelatedTo--> Smell <--RelatedTo--> Test <--RelatedTo--> Questionnaire 
Sudden <--RelatedTo--> Fast <--RelatedTo--> Fall <--RelatedTo--> Airplane <--RelatedTo--> Arrive 