Answer:
Explanation:
The answer is (c) natural disasters.
Westward expansion meant that the US acquired ever increasing amounts of land, and needed people, farmers, to settle there so it could maintained without a huge military presence
Fire is important because it cooked food, provided light and provided heat
It's false by adding access to waterways will have an greater impact on waterways.
Answer:
<u><em>A waterfall is an erosional landform, which occurs where there is a layer of hard rock on top of a layer of softer rock. Erosional processes such as hydraulic action and abrasion occur as the river flows downstream, however differential erosion takes place as the softer rock erodes faster.</em></u>
Explanation: