His action was alternately vivacious and sullen. pay close attention to the words in the sentence. what meaning is the author trying to convey?

Explanation:

The author is trying to say, the person being described has two defining characters. At a point in time, he can be very lively and animated. Some other times, he is withdrawn, cool and lonely.

The figure of speech to describe this is an OXYMORON.

after the moon goes from a full moon it turns into a waning gibbous moon.

here's where my answer came from. i hope this .