Why does the narrator say Holmes avoids emotions like love?

Because they could disturb his precise reasoning (Emotions would "introduce a distracting factor which might throw a doubt upon all his mental results.")

"Abhorrent" as used here most nearly means:

deeply distasteful (Emotions were "abhorrent" to his mind, that is, repugnant or hateful to it.)

How does the narrator characterize Holmes overall?

As a flawless reasoning machine wary of emotion (He calls Holmes "the most perfect reasoning and observing machine" for whom emotion would be a liability.)

According to the narrator, what does Holmes always call Irene Adler?

The woman (The passage opens, "To Sherlock Holmes she is always the woman," and the narrator adds that he has seldom heard Holmes mention her under any other name.)

The Woman: Level 3 Reading Comprehension Questions

To Sherlock Holmes she is always the woman. I have seldom heard him mention her under any other name. In his eyes she eclipses and predominates the whole of her sex. It was not that he felt any emotion akin to love for Irene Adler. All emotions, and that one particularly, were abhorrent to his cold, precise but admirably balanced mind. He was, I take it, the most perfect reasoning and observing machine that the world has seen, but as a lover he would have placed himself in a false position. He never spoke of the softer passions, save with a gibe and a sneer. They were admirable things for the observer — excellent for drawing the veil from men's motives and actions.

But for the trained reasoner to admit such intrusions into his own delicate and finely adjusted temperament was to introduce a distracting factor which might throw a doubt upon all his mental results.

Source: Arthur Conan Doyle, A Scandal in Bohemia (1891). Arthur Conan Doyle, The Adventures of Sherlock Holmes (1891). Public domain.

Comprehension questions