Metal is related to Salt. Salt can be used for Survival. 
Gain is a synonym of Accept. Accept is a synonym of Consent. Consent is the opposite of Oppose. Oppose is a synonym of Pit. 
Metal <--RelatedTo--> Salt --UsedFor--> Survival 
Gain <--Synonym--> Accept <--Synonym--> Consent <--Antonym--> Oppose <--Synonym--> Pit 