Radio was not an important invention in the early 20th century. Instead it was developed by Heinrich Hertz in the 18th century.
The cotton gin (APEX)
Chat with our AI personalities
The end of British rule in the Indian sub continent and the emergence of India and Pakistan as independent states was the most important event in this part of the region in the 20th century.
The similarities between the 20th and 21st centuries lie in innovations. The 20th and 21st centuries have been periods of great strides in technology and other areas.
17
: The first Kodak camera
Amendments 16-27 were all passed during this century: 20th.