What helped to make the First World War such a long and deadly war? large land areas that troops had to travel over

spy satellites and wireless communication

inventions like the airplane and the machine gun

alliances between Spain, the United States, and Canada

c

Explanation:

a historian researching the immigration policies of the early 1900s would expect a source written today,rather than in 1910 to :

( a ) be more interested in objective data and statistics.

native american contribution: the patriots from britain learn how to hunt, fish, and introduce diversity within cultures.

african americans: indirectly introduced the idea of diversity to americans. africans coming to america because of slavery taught white americans that people come from different backgrounds and colors. it also built america's economic stability for a great period of time. 

women: make america what it is today. there are some societies that are in the world currently that do not give women the same right we give women here in the united states. because women have rights here in the united states, other countries' citizens strive to come to america, especially women, since they have equal rights in the united states. this is important because america is seen and desired by many in the world. 

children: children are our future. we learn from our elders and carry out things the same or differently learning from america's history. we continue tradition and change tradition if it is needed.