Open Door Policy is a policy that helped incorporate china in trade with many other countries before World War 1. This is also closely related to imperialism.
The assassination was closely related to nationalism
We need more people in the Army!
World War 1 started officially when Archduke Francis Ferdinand was assassinated.
There was another fighting method called submarine warfare, which including the famous u boats.
World war 1 was a horrible time when many people on both sides died
This is trench warfare, where both sides dig bar down to build a base. These same trenches can reach up to many miles
They also use to use poison gas and this caused the creation of gas masks
This treaty held Germany accountable for causing the whole war, and this led to Germany facing many harsh consequences, such ass loss of land