Question

what is a trench warfare
that was use during WW1

Answer 1

In trench warfare, the soldiers dig trenches, maybe 4 or 5 feet deep and several feet long. The soldiers station themselves in these trenches, fire their guns at the enemy, and then duck their heads to avoid the enemies bullets.

For more information, read this article.

http://en.wikipedia.org/wiki/Trench_warfare