I assume you mean WWI as there were only two. In WWI Americans participated. Many of the able men went to war. While the women, children, and disabled stayed and helped with the war effort. Most of the effort back home was from the women.
France lost to britan because of their control of canada and many other great territories
Slash and burn agriculture is most often practiced in places where open land for farming is not readily available because of dense vegetation
The 21 Demands (of Japan). In 1915 Japancame up with the odd idea of trying to make the whole of China a protectorate – a protectorate of Japan of course. The Great War started in 1914 and Japan promptly declared war on Germany, in order to take over that country's leased territory in China.