an inexhaustible wall is a mean of renewable genetics & to be inexhaustible experiments to always be available ->  an inexhaustable resource is a kind of renewable resource that is always available  an inexhaustable resource is a kind of renewable resource that is always available & unwind is an inexhaustible rusting ->  wind is a kind of renewable resource that is always available  wind is a kind of renewable resource that is always available & unwind is a sink of matter & an matter sink is a mean of birds -> wind is a kind of renewable energy source that is always available