On your first day in the front line trench a "vet" comes over to talk to you and your mates. He looks very serious. "O.K. Private," he says, "You passed your training in Britain, but now your real training starts. Forget about everything they taught you at camp. Now it's learn fast or die!"

Here are some of the challenges we face every day in the trenches. Let's see if you know how to survive!

Your buddy gets caught in No Man's Land and is shot. He's only a few metres away from the trench and lying there, calling in pain. What do you do?