The year 20,000 B. C. Was how many years ago ?

In a command economy, people are not free toa buy consumer goods. b work in factories. c make production or monetary choices. d receive an education.

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.

1. what was william harvey's discovery about the human body? @ two types of blood flowed through the veins and arteries. b four fluids existed in the body: blood, yellow bile, black bile, and phlegm. © the same blood flowed through the veins and arteries. d ancient ideas of human anatomy and bodily functions were wrong. done