First, its Please, second:
1. D
2. D
3. F
4.D
5. F/D
6.F/D
7.D
8.D
9.F/D
10.D
11.D
12.F/D
13.F
14.D
15.F/D
WWI was caused by many things, among them was the assassination of Franz Ferdinand leading to the Austria-Hungary empire declaring war on Serbia which dragged most of Europe into the war due to alliances. The U.S. entered the war due to Germanys war tactics and the Zimmermann note.
People moved West because the government offered new settlers a lot of land for farming at a very low cost
Answer:
The threat of the grwoing power of Nazis
Explanation:
The correct answer is: An asteroid impact.
The scientists call it the extraterrestrial impact theory. It states that a giant, six mile wide meteor hit the Earth around 66 million years ago. As a consecuence, clouds of iridium dust and other materials were thrown into the air, blocking the sunlight for years. This lead to the extintion of the dinosaurs who were not able to feed themselves as plants didn't grow. Photosynthesis was not possible and food chains could not be completed. When the dust settled the greenhouse gases were locked in the atmosphere causing a general increase of temperature.