Early Middle Ages, help if you understand these. Brainliest will be involved number 1 & 2

Why did european nations face financial challenges after world war 1?

What occupation did muhammad have before the first revelation? politician military general trader religious leader mark this and retum save and exit

Which statement about submarine use in world war i is true? the allies never found a way to counter german submarine warfare. germany’s use of submarines affected the united states’ decision to enter the war. only the germans used submarines in world war i.