Answer:
Definition: U-shaped valleys form through glacial erosion. Glaciation develops in established v-shaped river valleys where the ice erodes the surrounding rocks to create a “U” shaped valley with a flat bottom and steep sides. Glacier movement is driven by gravity
The Mongols, a tribe of Nomads from Central or North Asia, who were ruled by Genghis Khan at the time.
I believe the answer is C. This is because all three headlines include information about transportation systems (first one with air delays, second with road closures and third with roads being reopened) being effected by natural disasters.
Here are why the other ones are incorrect:
A. In headline 2 with Arizona, it states how wildfires caused road closures around the state and not the area of the wildfire (headline 1 also disproves this answer, since it says “Worst delays since 9/11”, meaning it effected a lot more than the nearby area).
B. None of these are predicting natural disasters occurred, as seen by some of the language: “Arizona Fires FORCE road closures” (present tense, not past).
D. These do not mention anything about railroads being immune, so it can’t be it.
Hope this helps!
C
Given that the World population changed little between this time, we can gather than the birth and death rates were similar, since they seem to cancel each other out from 1200-1400. To clarify, think of this. If you add something to a total (think births to population), but take away the same number (think deaths from population) you end up with the same total as before. Because of this, A is the correct answer choice (The birth rate and death rate were about equal).