What advance improved communications during world war i?

 The correct answer is :  In 1917 appeared in the armies of Britain and France, new telephone switching equipment that made communications much more effective. Also appeared telephone networks that resisted more the effect of shellfire. The radios were very large and unreliable, also used pigeons, heliographs, flags, flares but were very limited in their use.

lincoln presided over the union victory in the american civil war, which dominated his presidency. a former whig, lincoln ran on a political platform opposed to the expansion of slavery in the territories. his election served as the immediate impetus for the outbreak of the american civil war.

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