Tanks became popular during World War I. They were used to -

destroy barriers and big walls stoping the solders way to the enemy’s and they were to destroy other enemy tanks and vechiles.

Explanation:

when world war i broke out across europe in 1914, president woodrow wilson proclaimed the united states would remain neutral, and many americans supported this policy of nonintervention. however, public opinion about neutrality started to change after the sinking of the british ocean liner lusitania by a german u-boat in 1915; almost 2,000 people perished, including 128 americans. along with news of the zimmerman telegram threatening an alliance between germany and mexico, wilson asked congress for a declaration of war against germany. the u.s. officially entered the conflict on april 6, 1917.

- a government ruled by the people, or assembly. officials monarchy - a single ruler like a king. over time some city-states, like athens would change governments. what this means is that all the citizens voted on all the laws.