1906 Germany launches U-1, the first U-Boat (for Unterseeboot). This modified Karp was 139 feet long, displaced 239 tons, and had a range of 2,000 miles, a surface speed of 11 knots, and a submerged speed of nine knots. It was joined in 1908 by a twin, U-2.
The submarines attacked Pearl Harbor
It sank up to 2,779 ships in world war 2
The Germans then threatened to use only Uboats for war and blew up a few ships.
it was used for World War I.
Bombs were invented during WWI, But they were not used until WWII.
because of the alliances the US had made previous to the start of the war along with the threat of the German Uboats attacking US civilians and property.
Enigma was used for war. Enigma was first invented by German engineer in World War 1.
the wright brothers
Jet engines were invented before WW2. They were used in a few late war German fighters.
No one knows who invented it, but it was invented in France for world war 1
Spitfires hadn't been invented at the time of WW1
toothpaste was used before the wheel was invented