Answer:
"He gave the struggle his attention, AS an idler might observe the feat of a juggler, without interest in the outcome."
Step-by-step explanation:
The term simile refers to what is similar, similar. Thus, this word is much used when comparing two elements / objects of different contexts, but that have some common characteristic, establishing the similarity.
For this reason, we can conclude that the phrase that shows the use of the simile in this excerpt is "He gave the struggle his attention, AS an idler might observe the feat of a juggler, without interest in the outcome." Because this sentence shows a comparison between two terms.