Uhm... Travel?
A bridge
list of rivers,mountains,plains,and valleys
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.
Yes. Many.
Yes
Erosion
They are dried out rivers most scientists think. so you can call them rivers yes
what can you study of the natural featurs of a place or region such as its mountains valleys deserts and rivers
valleys canions caves
They are examples of geography.
A bridge.