Answer:
A word is missing in line 7.
The missing word is 'had'.
Step-by-step explanation:
In the seventh line of page 184, the word, 'had', is missing. If this word is placed after the word, 'who', then the sentence will have a more complete meaning. Had is the past tense and past participle of the verb, 'have'. It is used together with the past participle taken to make a complete meaning.
Thus, the correct rendering of that sentence will be,
On one of my rare visits to school, a teacher who had taken an interest in me...