Interjecting "ums", "uha", and "hmm" into a conversation to signal that we are listening and interested in the conversation is called back-channel cues

Why did American audiences embrace the film noir, with its dark moodiness that marked a dramatic departure from the lavish spec¬tacle and optimism characteristic of Hollywood films in the 1930s?

What will be an ideal response?

It is best to begin choosing a topic

A. as early as possible to ensure adequate preparation time. B. close to the time of the speech to ensure it is up to date. C. before conducting your audience analysis so you can ask them questions about which of your ideas are best. D. when you will be free to work on it for a prolonged period so you can focus.