Annual is related to Year. Year is related to Yard. Backyard is a type of Yard. you are likely to find Gate in/at/on Backyard. 
Metal is related to Positive. Positive is related to Charge. 
Annual <--RelatedTo--> Year <--RelatedTo--> Yard <--IsA-- Backyard <--AtLocation-- Gate 
Metal <--RelatedTo--> Positive <--RelatedTo--> Charge 