Question

add commas, semicolons, or colons if needed. otherwise, submit the text without any additional punctuation. in the early part of the twentieth century, magazines newspapers movies and radio were the mass media of popular culture.

Explanation:

This uses the Oxford comma (the comma before "and") for clarity in listing multiple parallel items (magazines, newspapers, movies, radio) that are the mass media being referenced. Commas separate each item in the series to avoid confusion.

Answer:

In the early part of the twentieth century, magazines, newspapers, movies, and radio were the mass media of popular culture.