Crash course Is an excellent way to prepare for your paper 3 examine, plus a helpful reminded.
IB will cover anything from technology advances from World War 1 to World War 2. With this being said, for example during WW1 it was considered more of a trench warfare unlike during WW2 air crafts and other forms of methods of travel became more available.
Know the difference between Single Party States and Multi Party States
Understanding the difference between foreign intervention, two great Civil Wars that demonstrate this the most is the Chinese Civil War or the Spanish Civil War
During WW1 the Soviet Union (Russia) was not heavily involved unlike during WW2
Gather Historian views such as AJP Taylor who wrote the Origins of the Second World War, even just one historian will show you understand the topics
Gather old IB examines and choose several questions from each topic to work out and gather more information
Choose something you’re passionate about, when I took my examine I studied China a lot so I could write about Mao Zedong’s rise to power, the Chinese Culture Revolution, or even the the Great Four Leap Forward
When Talking about Multi Party or Single Party states, look up how each one for example Germany Vs China treated women, education, etc
Be able to tie in anything including how the person who was head of the state lived, for example Mao grew up on a farm or Juan Peron married Evita who helped bring in social reforms and women’s rights which guaranteed him his presidency.