What was the difference between Marceau performances
and the silent movies?

Although Marceau never spoke on stage, he did once famously speak in a film. He appeared in Mel Brooks' Silent Movie in 1976 and said the only word: "non". Off stage, like one of his heroes, Harpo Marx, he was a very talkative man. "Never get a mime talking," he once said.

Explanation:

quite an interesting way to teach topic sentences, because the answer to this question is the best definition of a topic sentence that one can present, it is as if answering the questions taught you how to do it, this is some real teaching, it is terribly well-done.

the topic sentence in this paragraph is:

topic sentences writers stay on track and keep a paragraph from becoming an aimless collection of sentences about an idea.

which incidentally tells you what a topic sentence should be.