Passage Two America’s national parks are like old friends. You may not see them for years at a time, but just knowing they’re out there makes you feel better. Hearing the names of these famous old friends-Yosemite, Yellowstone, Grand Canyon-revives memories of visits past and promotes dreams of those still to come. From Acadia to Zion, 369 national parks are part of a continually evolving system. Ancient fossil beds, Revolutionary War battlefields, magnificent mountain ranges, and monuments to heroic men and women who molded this country are all a part of our National Park System(NPS). The care and preservation for future generations of these special places is entrusted to the National Park Service. Uniformed Rangers, the most visible representatives of the Service, not only offer park visitors a friendly wave, a helpful answer, or a thought-provoking history lesson, but also are skilled rescuers, firefighters, and dedicated resource protection professionals. The National Park Service ranks also include architects, historians, archaeologists, biologists, and a host of other experts who preserve and protect everything from George Washington’s teeth to Thomas Edison’s wax recording. Modem society has brought the National Park Service both massive challenges and enormous opportunities. Satellite and computer technologies are expanding the educational possibilities of a national park beyond its physical boundaries. ① Cities struggling to revive their urban cores are tuming to the Park Service for expert assistance to preserve their cultural heritage, cities thirsty for recreational outlets are also working with the NPS to tum abandoned railroad tracks into bike and hiking trails, as well as giving unused federal property new life as recreation centers. ② To help meet these challenges and take advantage of these opportunities, the National Park Service had formed partnerships-some dating back 100 years, some only months old-with other agencies, state and local govemments, corporations, American Indian tribes and Alaska Natives, Park Friends groups, cooperating associations, private organizations, community groups and individuals who share the National Park ethic. Why are America’s national parks like old friends

A. Because they are always out there.
Because they are very old.
C. Because they make people feel better.
D. Because they are very famous.