Escaping a war in one's country of origin as a reason for immigrating to another country is an example of a
pull factor.
push factor.
migration pull.
migration push.

this isn't a question and if you're going to list things be kind and use commas.

c. troops marched forward in close formation against newer, more accurate weapons

it made them more prductive and efficent but with the change of polcies less and les got into the navy