Answer: Aqua ducts; sewer
Explanation:
Aquaducts can be defined as the structures that is used to conduct water from an area where it available in abundant amount to an area where it is in less amount.
It is referred as a system of pipes, canals, tunnels and other structures that carry water from source to the distribution point.
Romans also built sewer system which was covered by stones. Water flushed from the homes through the central channel into the main sewage. From there it moved to the stream or nearby river.