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One reason for hope lies in the extraordinary nature of human intellectual accomplishment. A hundred years ago, the idea of a man on moon, of the Internet remained in the realm of science fiction. Yet we have seen those things and much more. So, now that we have finally faced up to the terrible damage we have inflicted on our environment, we are working to find technological solutions. But technology alone is not enough. We must engage with our hearts also. Even companies once known only for profits are having a change of heart. For example, Conoco, the energy company, worked with the Jane Goodall Institute (J.G.I.) in Congo to build a sanctuary for orphaned chimpanzees. Another reason for hope is the resilience of nature—if it is given a helping hand. Fifteen years ago, the forests outside Gombe National Park in Tanzania had been virtually eliminated. More people lived there than the land could support. J.G.I, initiated the Lake Tanganyika Catchment Reforestation and Education Project, a program active in 33 villages around the park. Today people improve their lives through environmentally sustainable projects, such as tree nurseries and wood lots. We provided health care, family-planning and education programs, especially for women. As their education increases, their family size tends to drop. While pollution still plagues much of the world, progress is being made. This May in Sudbury, Ont., I saw new forests that were recolonizing hills destroyed by 100 years of nickel mining. The community raised the money and worked for months spreading lime and planting vegetation on the blackened rock. Animal species on the brink of extinction can be given a second chance through protection and captive breeding—even if preserving a habitat conflicts with economic interests. A company in China planned to build a rapid-transit line right through the only major remaining breeding ground of the rare pheasant-tailed jacana. There was an outcry, but it was the only economically viable route. Environmentalists worked with the company to come up with a solution—moving the breeding ground. Water was diverted back into nearby wetlands that had been drained by farmers, and suitable vegetation was replanted. I derive the most hope from the energy and hard work of young people. Roots & Shoots, J.G.I.'s program for youth from preschool through university, is now active in 70 countries. The name is symbolic: roots and shoots together can break up brick walls, just as citizens of Earth together can overcome our problems.
单选题21."A man on moon" and "the Internet" in the first paragraph are given as examples to show______.