There were 2 groups of countries the Axis Powers and The Allies, but I would say Germany and The United States were the 2 main countries
They didn't, they used gas which was against international law.
Https://www.quora.com/Is-it-true-that-the-USA-dropped-more-bombs-on-Laos-during-the-Secret-War-than-...
true
Answer:
The assassination of the heir to the heir to the Austro-Hungarian throne, Archduke Franz Ferdinand, and his wife, Sophie. On June 28, 1914, the couple paid a state visit to Sarajevo, the capital of Bosnia.
Explanation:
