The last one should be the correct one
Britain entered World War I in 1914 to honor a treaty that promised to defend Belgium and to fulfill an alliance with France and Russia. The Germans attacked Liege, Belgium, in the first battle of World War I, and then marched on to attack France.
I'm assuming by "war" you mean World War I
I think 19 but slave states were 15
I’m not sure hopefully it’s correct
Adolf Hitler wrote the book "my struggle" in prison. it describes his life and his struggles as said in the title.
His inventions sped production. This made life easier. This also made things faster for everyone.