Teacher: In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.
Teacher: Now, understand the problem? If you are still confused, see the following example:
Passage: Nearing London, Oliver encounters Jack Dawkins, a pickpocket more commonly known by the nickname the "Artful Dodger", and his sidekick, a boy of a humorous nature named Charley Bates, but Oliver's innocent and trusting nature fails to see any dishonesty in their actions. The Dodger provides Oliver with a free meal and tells him of a gentleman in London who will "give him lodgings for nothing, and never ask for change". Grateful for the unexpected assistance, Oliver follows the Dodger to the "old gentleman's" residence. In this way Oliver unwittingly falls in with an infamous Jewish criminal known as Fagin, the gentleman of whom the Artful Dodger spoke. Ensnared, Oliver lives with Fagin and his gang of juvenile pickpockets in their lair at Saffron Hill for some time, unaware of their criminal occupations. He believes they make wallets and handkerchiefs.
Solution: Who believes Fagin's gang make wallets and handkerchiefs?.
Reason: This question is based on the following sentence in the passage "He believes they make wallets and handkerchiefs". It evaluates the understanding that the pronoun "he" refers to name "Oliver". You can ask questions like this one about most pronouns in a paragraph.

Now, solve this instance: Passage: De Long's party found no immediate sign at their landing-place of any human habitation, and had only a sketchy idea of where they were—Petermann's map provided few useful details. On September 19, having buried their non-essential possessions in a mound marked by a tent pole, they set out in search of settlements. Progress was hampered by the poor physical condition of the men, in particular Eriksen, who was badly affected by frostbite. On September 21 they halted at two empty huts, probably part of a hunting camp, where Alexey raised spirits by shooting a deer to replenish their dwindling food stocks. De Long allowed his exhausted party several days' rest before resuming the march.On September 28 the party found a large hut, with signs of recent occupation–edible food in the store, and moccasin tracks in the snow. When searches in the locality brought no sign of people, De Long decided to move on. By October 4, Eriksen could not continue; the party halted at another abandoned hut where, on October 6, Eriksen died. On October 9, with the condition of several men worsening, De Long decided to send two of the fittest in the group, Nindemann and Noros, to seek help. Ambler was offered the opportunity to go with them, but felt that his duty as a doctor required him to stay with the main body.For the next week De Long's party struggled on, sometimes making barely a mile a day. Although they jettisoned more of their possessions on the way, De Long insisted on carrying his maps and journals. His entry for October 10 recorded that there was "nothing for supper but a spoonful of glycerine". A few days later Alexey, the group's principal hunter, shot a ptarmigan which provided soup. But Alexey was weakening, and on October 17 he died.On October 20, trapped by the weather and without supplies, the party came to a final halt. Throughout the march De Long had written up his journal each day, but after October 20 his entries became intermittent, largely limited to terse statements of the dying and the dead. He noted the deaths of Kaak and Lee on October 21, Iverson on the 28th, Dressler on the 29th. His last entry, dated October 30, records the deaths of Boyd and Görtz and ends "Mr Collins dying".
Student:
What are the exact names of the two people with whom Ambler was offered the opportunity to go?