All pet birds need 12 hours of dark, silent sleep each night to maintain their good health.
(All pet birds; need; 12 hours of dark, silent sleep each night; to maintain their good health) Context(All pet birds need,List([0, 18))):(All pet birds; need 12 hours of dark, silent sleep each night to maintain; their good health)
All pet birds need,List([0, 18))
All pet birds All pet birds
need need 12 hours of dark, silent sleep each night to maintain
12 hours of dark, silent sleep each night to maintain their good health
their good health