Answer:
Gas masks used in World War One were made as a result of poison gas attacks that took the Allies in the trenches on the Western Front by surprise. Early gas masks were crude as would be expected as no-one had thought that poison gas would ever be used in warfare as the mere thought seemed too shocking
I believe the correct answer is B
To that end, Congress passed the Selective Service Act, which Wilson signed into law on May 18, 1917. The act required all men in the U.S. between the ages of 21 and 30 to register for military service. Within a few months, some 10 million men across the country had registered in response to the military draft.
So it is D
Answer:
The large number of groups could lead to ethnic tensions.
Explanation:
