The answer is Trench Warfare the gas masks were not that effective back then and gas raises so if you were in a trench for the most part you would be fine but they did both.
The Anglo-French War influenced economies everywhere throughout the world. Both Britain and France owed tremendous war obligations to the United States and depended on preparation installments from Germany to pay their advances. England was profoundly in the red, with high unemployment and low wages.
Because there are fossils left as evidence of the existence.