How can a member of Congress officially change a bill? by meeting in conference committee
by passing an amendment to the bill
by requesting a pocket veto from the president
by gathering two-thirds of congressional votes

i think by meeting in conference commitee

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.

world war i began in 1914, after the assassination of archduke franz ferdinand, and lasted until 1918. during the conflict, germany, austria-hungary, bulgaria and the ottoman empire (the central powers) fought against great britain, france, russia, italy, romania, japan and the united states (the allied powers). to new military technologies and the horrors of trench warfare, world war i saw unprecedented levels of carnage and destruction. by the time the war was over and the allied powers claimed victory, more than 16 million people—soldiers and civilians alike—were dead.

explanation: