people build briges
Bridges
People build bridges to cross deep rivers or valleys. Bridges are structures that span a gap or obstacle, providing a safe passage for people, vehicles, and goods to cross over. They are often constructed using a variety of materials such as concrete, steel, or wood, depending on the location and purpose of the bridge.
A bridge.
A bridge.
they build dams
bridges...
the river might erode the land around it causing the peoples houses to fall in and also the people have to build a bridge across to cross it and get to the other side
they use to cross the river in cannoe or in ferry
A bridge
Dams are built to create reservoirs.
People in south America build dams on the major rivers to get more electricity. Plus, there is more industrialization in the area.