What is federalism and can you give me an example of how it works?

What are the two powers that the federal and state governments share?

What is the relationship between the supreme court and the lower courts? the supreme court must abide by the decisions of the lower courts. the supreme court appoints judges to the lower courts. the supreme court can overrule decisions made by the lower courts the supreme court can impeach judges from the lower courts.

At the beginning of the war, why was hitler allowed to continue his aggression without resistance from other european countries