Spend is a synonym of Exhaust. Exhaust is a type of Waste. Waste is related to Lose. 
Obvious is related to Clear. Clear is related to Wind. Wind is related to Energy. Energy is related to Fuel. 
Spend <--Synonym--> Exhaust --IsA--> Waste <--RelatedTo--> Lose 
Obvious <--RelatedTo--> Clear <--RelatedTo--> Wind <--RelatedTo--> Energy <--RelatedTo--> Fuel 