Digital ACT Reading Practice Question #1700

According to the passage, closed-loop hydroponic facilities save water primarily by: Passage Excerpt (Social Science): As metropolitan centers swell toward megacity status, conventional food supply chains transporting produce across thousands of refrigerated miles face logistical and ecological bottlenecks. In response, urban agronomy has evolved from community gardening into capital-intensive vertical farms in repurposed warehouses. Utilizing automated nutrient-film hydroponics and narrow-spectrum LED lighting tailored to chlorophyll absorption, these closed-loop facilities yield up to forty times more leafy greens per square foot than open fields, while consuming ninety-five percent less water. Critics, however, emphasize substantial grid energy demands for climate control and artificial lighting. Analyst Dr. Elena Ramos argues that until municipal grids transition to low-marginal-cost renewable power, carbon abatement benefits remain localized rather than systemic.