"Superposition is another feature that is peculiar to quantum systems. Before a quantum object is measured, it does not have definite characteristics. Instead, it exists in a superposition of multiple mutually contradictory states--allowing it to be in two places at once, for example."
As this is stated, superposition is not a perculiar quantum effect. Any macroscopic object on which there hasn't been any measurement is in fact in a superposition of mutually excluding states, each state being affected a probability term.