Why was the arrival of American forces so important to the war effort?

In 1917 almost two million American soldiers arrived in Europe. These additional troops bolstered the European Allied forces and hurt the morale of German troops. The deployment of these American troops helped break holes in the German lines, and eventually the German's retreat. These additional troops provided the necessary manpower to help end the war

when studying cause and effect, historians usually group the causes into different categories. for example, cultural causes reflect how a society’s literature and art convey the way the society saw itself in relation to the rest of the world. another resource that historians use to understand society is pop culture, which tells them the trends and ideas that are preferred by the common people. when studying cause and effect, it’s important to remember multiple causation, or the idea that an effect could have several causes and vice versa.  

the correct option is “cultural causes” since art and literature are related to the culture of a place. culture is determined by literature, art, music.

the correct option is “pop culture” since it reflects the likes and ideas of common people whereas the rest of the options do not focus on common people.  

the correct option is “multiple causation” since it refers to the idea that events are caused by multiple reasons, not just a single one.  

d) post-world war i