When Cursed Oasis enters the battlefield, sacrifice it unless you pay .
: Add to your mana pool.
: Add or to your mana pool. Each opponent gains 1 life.
When Cursed Oasis enters the battlefield, put a -1/-1 counter on target land.
.
: Add 
to your mana pool.: Add or 
to your mana pool. Each opponent gains 1 life.
