Im writing this to finish a challenge
Answer:
Refugees
Explanation:
As millions of refugees without any home or place to go wanders all over Europe
Answer:
I learned this not too long ago too!
I think the answer you are looking for is parallax. Hipparchus used parallax to not only measure the distance from the sun, but also the moon. Although he was off my a couple hundred yards or so he actually measured the moon before the sun.
it allowed France and Russia to mobilize their militaries faster than Germany had thought possible.