When Bog Burrows enters the battlefield, return a land you control to its owner's hand.
: Add or to your mana pool.
Put Bog Burrows on top of your library: Add to your mana pool.
: Return Bog Burrows to its owner's hand.
: Add 
or 
to your mana pool.
to your mana pool. : Return Bog Burrows to its owner's hand.
