By building and maintaining dams, busy beavers can completely change the vegetation, animal life, and other components of the watersheds in which they live.
(busy beavers; can completely change; the vegetation, animal life, and other components of the watersheds) (they; live; L:the watersheds)
busy beavers they
can completely change live
the vegetation, animal life, and other components of the watersheds
L:the watersheds