10.—What precautions may be taken against capture of fire-trench?
11.—What does trench warfare correspond to in open warfare?
12.—What does the safety of a sector depend on?
13.—What is the fundamental duty in trench warfare?
14.—What rule determines the number of men to be posted in the fire-trench?
15.—Sum up their orders about firing before open terrain, before covered terrain.
16.—What is meant by double sentinels?
17.—Why is listening attentively even more important than keeping a sharp look out?
18.—Why should the sentinels refrain from answering the enemy's fire?