as the amount of available water decreases , tree-growth rings will become narrower & width is a property of size / shape and includes ordered values of narrow / wide ->  as the amount of available water decreases, the width of tree-growth rings becomes narrower  as the amount of available water decreases, the width of tree-growth rings becomes narrower & if something causes something else then the result of that something else indicate the properties of that something ->  the width of a tree-growth ring indicates the amount of available water  the width of a tree-growth ring indicates the amount of available water & a tree growing a tree-growth ring occurs once per year ->  the width of tree-growth rings indicate the amount of water available during the year they were formed  the width of tree-growth rings indicate the amount of water available during the year they were formed & dry environments result in narrow tree-growth rings -> a narrow tree-growth ring indicates a dry year