Final answer:
The author's comparison in paragraph 10 provides insight into Helen Keller's mental state and emphasizes the importance of language and communication in her life.
Step-by-step explanation:
The author's comparison in paragraph 10 provides insight into the mental state of Helen Keller. The author compares Keller's preliterate life to a ship lost in the fog, suggesting that she felt lost and uncertain in her early experiences before gaining the ability to communicate. This comparison helps the reader understand the challenges Keller faced and emphasizes the importance of language and communication in her life.