How do we know what happened in the past ?

People know what happened in the past by looking at things from the past including sources (like books, newspapers, and letters) and artifacts (like pottery, tools, and human or animal remains.) ... People can learn about the past by talking to people who remember things that happened at some point in the past.

the answer is typhoon

this means that germany had to pay the allied countries. reparations are/is essentially payment for something that they have done wrong, so after ww1, germany was forced to pay reparations so they could replenish the allied countries resources' that they had lost during the war.