4. Armored Vehicles/Tanks.
5. Bomber Planes.
6. Man V. Machine
7. Gas.
8. Gas Masks.
9. Artillery.
10. Trench Club
Also, you got things wrong in Number 1 and and 3, Let me fix it :
1. Espionage/Spies
3. No-man’s Land, Because if someone would go through No Man’s Land Alone, they would simply be shot by the Machine Guns mounted in the Opposing Trench.
