two elements

As a sample of the way you would write the book you have chosen to send in two elements.

background to WWI

1. a background piece on World War I - short, but containing the essential facts – like when did it take place, who was fighting who, what weapons were used, how many soldiers were enrolled, how many were killed, injured, who won and so on.  You are going to be concentrating on the European part of the fighting.

a battle - or something else

2. an account of some aspect of the war - a battle, trench life or something.  Again a short account, but you should include information from various viewpoints - and allow your own views to shine through.