【答案解析】Chengde Summer Resort is a place of interest. There are a lot of tourists from many different places, especially during weekends and holidays. Several years ago, some of them paid no attention to the environmental protection. They spit on the ground, and threw the rubbish here and there. Worse still, they wrote their names or some sentences on the stones or walls. To our joy, great efforts have been made by the local people and changes have taken place. The tourists carry plastic bags with them. In addition, they take many beautiful pictures. It"s clear that people have realized the importance of environment.