Today, in our environmental science lecture, we will discuss the impact of urban farming. One key point is that rooftop gardens can reduce a building's energy consumption by up to 25% because they provide insulation. However, the initial cost of setting up such a garden is high, and maintenance requires daily watering unless a drip irrigation system is installed. Interestingly, a recent study in Chicago found that community gardens not only improve local food access but also increase property values within a 500-meter radius by about 7%. Yet, the main challenge remains the availability of land in dense cities, which is why vertical farming is gaining popularity, though it is more energy-intensive.
❓ According to the lecture, what is the main challenge for urban farming in dense cities?
A. A. The high initial cost of setting up rooftop gardens
B. B. The need for daily watering without a drip irrigation system
C. C. The limited availability of land in densely populated areas
D. D. The increase in property values affecting local residents
✅ 正确答案
C. The limited availability of land in densely populated areas