The national parks are areas of diverse interests and it is precisely (1) __________ the national parks enioy a tremendous popularity that many scientific issues have (2) __________ to the for. The ultimate (3) __________ of our love affair with the parks has been that (4) __________ ever-increasing use of these areas the problems of urban living have found their (5) __________ into the parks. The irony is that these areas were originally (6) __________ of as places to escape the pressures and problems of civilization. Popularity has its (7) __________. The largely unseen “infrastructures”, sewage systems, water supplies and roads (8) __________, in national parks across the country, beginning to crack. In addition to getting old, some parks are also handling two to three times as (9) __________ visitors as thirty years ago, so they are experiencing increasing (10) __________ on their resources from visitors.