11.   The students are working under the guidance of park rangers.

12.   Among the ads was a Kenyan park ranger typing into a Thinkpad laptop computer as he observed a baby elephant joining a herd.

13.   An Army Reserve Chinook helicopter, the only one capable of flying in the thin mountain air, took five climbing park rangers to the summit Tuesday afternoon.

14.   And extra park rangers have been assigned to handle the crowd expected to watch the move.

15.   And in the Northern Territory annual flooding pushes cats into tree branches, as park rangers go out in boats at night and shoot them by the thousands.

16.   And Mike Whatley, the supervisory park ranger here, said attendance at the Thoreau talks has been excellent.

17.   Ask a park ranger about regulations or access www.floridaconservation.org.

18.   At the center, you might run across park ranger and self-taught accordionist Phil Rose playing Zydeco music on his squeeze box.

19.   At this point Morkel and other park rangers flying above try to identify the animal by the notches in its ears.

20.   At night, park rangers tell everything they know about the Grand Canyon with lectures and films.