Summarize how the U. S. raised an army for the war.

The Selective Service Act of 1917 authorized the government to raise an army for entry into WWI through a draft that drew them into conscripted military service. Under the Selective Service Act, all males aged 21 to 30 (later expanded to 18 to 45) were required to register for the draft lottery.

i think the answer is c, rivers.

explanation:

sometimes, borders fall along natural boundaries like rivers or mountain ranges. for example, the boundary between france and spain follows the crest of the pyrenees mountains. for part of its length, the boundary between the united states and mexico follows a river called the rio grande. the borders of four countries divide africa’s lake chad: niger, chad, cameroon, and nigeria.

b.   jim crow laws were enacted in northern states.