In world war i and world war ii, american indian soldiers played a critical role in the us military effort by using their native languages as the basis for creating successful codes. the most famous of these soldiers were a group of four hundred men known as the navajo code talkers. these innovative and courageous soldiers developed for the united states marine corps a virtually unbreakable military code, which proved highly valuable against the japanese during the second world war.
which words and phrases from this excerpt create a tone of admiration? check all that apply.

highly valuable

developed

native languages

courageous

critical role

military code