Which event occurred after the us senate failed to pass the treaty of versailles

What does the document of the birtish octopus is an uderlying cause of the world war 1

What is the main difference between primary and secondary sources? a. primary sources are historical documents, and secondary sources are modern-day documents. b. primary sources are derived from museums and archives, and secondary sources are created by history students and academics. c. primary sources are found in ancient places with a rich history, and secondary sources are found in historical journals and blogs. d. primary sources are created during a particular historical era, and secondary sources are created by studying primary sources.

Brainliesttt !me : ) -what is invisible warfare?