trench warfare

After trench-warfare days there was an incongruity in some episodes, which was not devoid of humour.

To maintain the normal semblance of trench-warfare was an easy task for the German, and one that he never failed in.

This process of relief and the general conditions brought a return of trench-warfare almost on its old lines.

Another extensive project in the trench-warfare program was the manufacture of the so-called toxic gas sets.