(Flooded Oasis isn't a spell.)
Flooded Oasis enters the battlefield tapped unless you pay .
Sacrifice a land: You gain 1 life.
: Add to your mana pool.
: Add or to your mana pool. Each opponent gains 1 life.
.
: Add 
to your mana pool.: Add or 
to your mana pool. Each opponent gains 1 life.
