Glass is related to Ground. Ground is the opposite of Roof. Roof is a type of Cover. Dust is a type of Cover. 
Bacteria is related to Disease. Aids is a type of Disease. Aids is a type of Virus. 
Glass <--RelatedTo--> Ground <--Antonym--> Roof --IsA--> Cover <--IsA-- Dust 
Bacteria <--RelatedTo--> Disease <--IsA-- Aids --IsA--> Virus 