What new technologies were invented during World War 1?

Automobiles and submarines.
Thanks, poison gas, ambulance.
Airplanes and reconnaissance.
Observational balloons and Zeppelin's.

In addition to the technologies you mentioned, several other new technologies were invented during World War 1. These include:

1. Trench Warfare: The extensive use of trenches as a defensive strategy was a new development during WW1. Trenches provided protection from enemy fire and allowed soldiers to hold their ground.

2. Machine Guns: Although machine guns existed before WW1, their use became much more widespread during the war. They had a significant impact on the nature of battle, often causing high casualties and making advances difficult.

3. Tanks: The first armored tanks were developed and used during WW1. While the earliest versions were slow and somewhat unreliable, they marked the beginning of tank warfare and had a profound impact on land battles.

4. Flamethrowers: Flamethrowers, which could shoot ignited fuel over a long distance, were used for the first time during World War 1. They were primarily used as a psychological weapon to demoralize enemy soldiers and clear out trenches.

5. Poison Gas: WW1 saw the large-scale use of chemical weapons such as chlorine, mustard gas, and phosgene. These gases were used as a means of breaking the stalemate of trench warfare by incapacitating or killing enemy soldiers.

6. Aircraft Carriers: The first aircraft carriers were developed during WW1, although their usage was limited. They served as platforms for launching and recovering seaplanes used in naval reconnaissance.

7. Radio Communication: Although wireless telegraphy existed before the war, its use became more crucial during WW1 for communication between soldiers on the front lines and headquarters. Radios in aircraft were also used for reconnaissance purposes.

8. Submachine Guns: The submachine gun, a lightweight firearm capable of fully automatic fire, was first developed and used during World War 1. It proved especially useful in trench warfare and close-quarter combat.

These technological advancements revolutionized warfare and had a lasting impact on military strategies and equipment used in later conflicts.