From Robert Louis Stevenson's essay *An Apology for Idlers* (1881). Select the word that fits the blank. "It is a sore thing to have laboured along and scaled the ______ hilltops, and when all is done, find humanity indifferent to your achievement."

The verbs *laboured along* and *scaled* tell you the climb has been hard. "Sore thing" + *humanity indifferent to your achievement* reinforce that the climber's effort has been considerable. The blank must therefore name a quality of the hilltops that *makes them hard to reach*. "Arduous" — difficult, requiring strenuous effort — captures exactly that. - "Distant" works thinly but doesn't carry the *effort* of climbing. - "Cheerful" or "modest" both undercut Stevenson's image of pained labour. *Arduous* derives from Latin *arduus*, steep. The original sense (a steep slope) and the GRE sense (difficult task) line up exactly with Stevenson's hilltop image.