The 1900s was more industrialized as a result of the industrial revolution, and there were a number of social reforms, such as suffrage for people of color and women. The 1900s also saw an end to traditional monarchy as a result of the 1917 Russian Revolution.
The Tet Offensive was a communist attack during the Vietnam war, and it was considered a turning point in the war. It was geared to slowly and painfully push America out of Vietnam.
Functional sees society as acting like an organism BECAUSE every aspect of society serves a specific function (like a cell, everything does something to contribute to the whole