Final answer:
The central conflict in "Through the Tunnel" is both internal, showcasing Jerry's struggle for independence, and external, involving the challenge of swimming through the underwater tunnel. This conflict underscores the theme of maturation. Similarly, in the Mark Twain excerpt, the internal conflict of self-doubt and external factors heightens the tension and reinforces the theme of relying on personal knowledge.
Step-by-step explanation:
The central conflict in the story "Through the Tunnel" by Doris Lessing is both internal and external. The protagonist, Jerry, is a young boy struggling with his desire for independence and the need to prove himself, which exemplifies the internal conflict. Conversely, the external conflict arises from the physical challenge of swimming through an underwater tunnel, a feat that symbolizes his passage from childhood to adolescence. This dual conflict drives the narrative forward and is crucial to the development of the story's theme, which revolves around the universal experience of growing up and the personal transformations that come with it.
In the Mark Twain excerpt mentioned, Twain experiences self-doubt, which is an internal conflict that adds depth to his character and emphasizes the theme: the importance of relying on one's knowledge and training. This internal conflict is accentuated by the presence of other people sent by Mr. Bixby, introducing an element of external conflict as these additions to the scene increase Twain's nervousness. By intertwining these conflicts, the author successfully builds tension and makes explicit the underlying message of the narrative.