1. Population Changes & Aging in China | Analyzing shifts in age groups, reasons for population aging, and differences in rural vs. urban demographics. 2. Urban Growth & Housing Issues | Examining traffic congestion, housing shortages in Milan, and comparing strategies for improving urban living conditions. 3. Drainage Basin & Flooding | Understanding water flow processes, causes of flooding, and how tree planting and reservoirs reduce flood risks. 4. Desert Climate & Vegetation Adaptations | Investigating temperature variations, reasons for low rainfall, and plant adaptations to arid environments. 5. Deforestation & Environmental Impact | Effects of deforestation on tropical rainforests, human-induced climate changes, and biodiversity loss. 6. Tourism & Economic Development | Benefits of tourism for local populations, challenges faced by tourist areas, and the role of national parks in conservation.