Centaur Aqueduct enters the battlefield tapped unless you control an enchantment.
: Add or to your mana pool.
Put Centaur Aqueduct on top of your library: Add to your mana pool.
Cycling (, Discard this card: Draw a card.)
: Add 
or 
to your mana pool.
to your mana pool. 
(, Discard this card: Draw a card.)
