There are some gaps in knowledge that should be filled as quickly as possible. It is truly worth remembering such tremendously important events, mainly to prevent history from repeating itself. Check a book on the topic or browse the Net; the advantages will be hard to underestimate!
You showed that the topic of the First World War was not new to you and that you were in possession of valuable knowledge that was used during the quiz. You may also decide to broaden your horizons and absorb even more data on the said military conflict.
You have answered almost all questions correctly, showing that it is simply impossible to confuse you with names, dates, and figures, as you know them all very well. Somebody must have passed his or her history exams impeccably, eh?