A．A simple lifestyle.
B．A more interesting life orientation.
C．Exciting outdoor activities.
D．Wildness and attraction of the nature.
A．It urges campers to treat its service with respect.
B．It urges campers to love the nature.
C．It shows respect to the nature.
D．It requires the campers to be clean in outdoor place.
A．St. John's University.
B．Massachusetts Institute of Technology.
C．University of California, Berkeley.
D．Yale University.