Final answer:
The passage represents internal conflict as Mark Twain doubts his abilities due to external pressures, within the framework of exposition which introduces characters, setting, and themes hinting at conflicts.
Step-by-step explanation:
The passage you've described seems to encapsulate internal conflict within a character as well as the concept of exposition. The character, represented by Mark Twain, initially feels confident in his abilities, but the introduction of other characters and their actions creates a tension that leads to self-doubt. This internal struggle is indicative of the theme where reliance on one's knowledge and training is paramount, as opposed to second-guessing oneself. The mention of exposition is significant here because it sets the stage for the internal conflict. It tells us who the characters are, the setting, and teases the themes and conflicts to come. As for theme, it broadly represents the message or the moral that resonates through the narrative, often tying together various elements of the plot.