The answer is D, because the Russian winter led to hypothermia and disease, causing hundreds of thousands of his soldiers to die.
There may be more, but some types of refugees are:
War
Social
Religious
Political
Racial
The water cycle starts with ground water. As it is heated up by the sun it evaporates, (or transpiration happens on plants and trees) and then condensation occurs as the new clouds form. Hope this helps!
Tectonic theory is ur answer
