Answer:
B. Rapid development of technology.
Explanation:
Airplanes were not a thing yet. Railroads were still the main form of transportation at that time.
The Mississippi-Missouri-Ohio river system is the largest and most significant river system in the world.
Answer:
Option (3)
Explanation:
Mid-oceanic ridges are the regions along which two distinct plates move away from one another. This type of plate boundary is known as the divergent plate boundary.
Whereas a rise occurs along a divergent plate boundary and is mostly associated with the region of hot-spots, where the magma is forced to rise up forming a gently steeper underwater highland area.
Both these features occur in a divergent plate boundary and plays an important role in pushing the continents apart. So we can conclude that the rises are mostly associated with the region of hot-spots, and ridges are formed due to the seafloor spreading at divergent plate boundaries.
Hence, the correct answer is option (3).
A cliff collapse could affect the environment by exposing new rock (previously covered by the cliff) to the elements, which could result in runoff of a different nature when it rains. Additionally, the cliff would collapse upon whatever life/features existed at the base of the cliff. One of the most drastic effects could be the shaking of the earth. Cliff failures can result in earthquakes or, if the cliff collapses into a large body of water, massive tsunamis which radically impact coastal environments.