Passage
Roman engineers built aqu____ to bring fresh water from distant hills into crowded cities. The channels sloped downward at a gentle, carefully calculated gra____ so that gra____ alone kept the water flowing. Where a valley int____ the route, workers raised tall stone arches to support the con____ high above the ground. Skilled sur____ used simple lev____ tools to measure the slope across many miles. Inside the channel, a wat____ lining pre____ leaks and kept the supply clean. On arrival, the water fed public fountains, private homes, and eno____ heated baths that citizens visited daily.