There was.....Africa Algeria Angola Anglo-Egyptian Sudan Basutoland Bechuanaland Belgian Congo British East Africa (Kenya) British Gold Coast British Somaliland Cameroon Cabinda Egypt Eritrea French...
302 trenches were made in world war 1.
It was a world war because it involved countries from different continents - Europe, North America, Africa, Asia, Australia.
Less than 400.
Trench systems were constructed by German , Russian , British and American combatants .