Was trench warfare the main method of fighting in world war i?

Yes and no. It depends on the front. On the Western Front, the war was mainly in trenches and was not dynamic almost at all. It was quite static and trenches were constructed so that the troops had as much comfort in them as possible. On the Eastern front, there were also trenches but it was not that static and the army was on the move most of the time so no high-quality trenches were needed in the East. overall I would say that the trenches were the main method but it depends on the stage and front of the war.

answer; i believe its (cpr);

it was douglas macarthur..