Por qué fray Bartolomé Arrazola tiene una mirada etnocentrica​

Dalton developed the first model of the atom that showed the structure of the inside of an atom

The rise of advertising in the 1920s. i am good with seeing how advertisements shape the roaring twenties and how it developed a new way of life through modern days. but i am not sure what the details of advertising in the 1920s were. if possible can you send me links (preferrably credential links) to sources that maybe show like the first company to start advertising through the radio, how advertising benefits (statistics graphs), etc.

The original term of was descriptive of lower-class people who performed manual labor.