The ancient Romans built special -----, called aqueducts
bridges
For thousands of years, people in Egypt have dug ----- and ditches to take water to their fields next to the river
canals
______ stopped the flooding and controlled the river.
A dam
Mexico City was built on a ------ , so it was very wet. The Aztecs invented a system of chinampos.
swamp
A chinampa is an ----- built on a lake.
island
Some animals live in ------ habitats—streams, rivers, and lakes.
freshwater
. In dry countries, farmers use ----- systems to water their crops.
irrigation
