Soft is related to Sigh. Sigh is related to Tired. Tired is a form of Tire. Tire is the opposite of Active. 
Mushroom is related to Bell. Bell is related to Machine. Machine can be used for Stretch. 
Soft <--RelatedTo--> Sigh <--RelatedTo--> Tired --FormOf--> Tire <--Antonym--> Active 
Mushroom <--RelatedTo--> Bell <--RelatedTo--> Machine --UsedFor--> Stretch 