Answer:
Politics
Explanation:
The most significant change in the late 18th and early 20th centuries is POLITICS.
This is evident in the major events that occurred and shook or change the world during this period.
For example, the French Revolution of 1789, affected Europe as monarchical and aristocracy style of government were challenged. The effects also reached the American colony, particularly the South and Central America.
Similarly, World War 1 in 1914, changed the course of action in the 20th century, as nations formed alliances, enemies, change style of government, and many more.
