Which of these things were elements of trenches? Check all that apply.

Barbed wire, protected dugouts, and parapets were features of trench systems. Barbed wire hindered enemy advances, dugouts gave soldiers shelter, and parapets were raised earthworks at the trench edge for protection. No-man’s-land was the exposed area between opposing trenches, not part of a trench itself.

AI-written and checked against the verified answer.