What was a result of the use of chemical weapons during World War I? Tanks and aircraft were developed to counter the effects of chemical weapons.
Trenches were used to protect soldiers from chemical weapons in battle.
Many nations agreed to stop using chemical weapons after World War I.
Doctors developed treatments that made chemical weapons obsolete.

Following archduke franz ferdinand's assassination, austro-hungarian leaders: a. aided the ottoman empire in its campaign to keep serbia under its control. b. executed nearly all prominent serbs living in austria-hungary c. threatened to invade serbia if serb leaders did not agree to a set of strict demands. d.. formed an alliance with great britain to protect austria-hungary from future attacks.

The articles of confederation allowed congress to: make and borrow money. declare war. create a postal service. all of these choices are correct.

Which historical interpretation is supported by this source?