Task: Question Generation
Input (English): Passage: Both men were suffering, but Mertz in particular started to feel ill. He complained of stomach pains, and this began to slow them down. Pavlova was killed, leaving only one remaining dog. Mawson decided to lighten their sledge, and much of the equipment—including the camera, photographic films, and all of the scientific equipment save the theodolite—was abandoned. On 29 December, the day they cleared the Ninnis Glacier, the last dog was killed. Mawson recorded: "Had a great breakfast off Ginger's skull—thyroids and brain". Two days later Mawson recorded that Mertz was "off colour"; Mertz wrote that he was "really tired [and] shall write no more".They made 5 miles (8.0 km) on 31 December, no progress for the following two days, and 5 miles more on 3 January. "[The] cold wind frost-bit Mertz's fingers" recorded Mawson, "and he is generally in a very bad condition. Skin coming off legs, etc—so had to camp though going was good." Not until 6 January did they make any more progress; they went 2 miles (3.2 km) before Mertz collapsed. The following day Mawson placed Mertz onto the sledge in his sleeping bag and continued, but was forced to stop and camp when Mertz's condition again deteriorated. Mawson recorded:
He is very weak, becomes more and more delirious, rarely being able to speak coherently. He will eat or drink nothing. At 8 pm he raves & breaks a tent pole. Continues to rave & call 'Oh Veh, Oh Veh' [O weh!, 'Oh dear!'] for hours. I hold him down, then he becomes more peaceful & I put him quietly in the bag. He dies peacefully at about 2 am on morning of 8th.
Strong winds prevented Mawson from continuing for two days. Instead, he prepared for travelling alone, removing the rearmost half from the sledge, and rearranging its cargo. To save having to carry excess kerosene for the stove, he boiled the remainder of the dog meat. Dragging Mertz's body in the sleeping bag from the tent, Mawson constructed a rough cairn from snow blocks to cover it, and used two spare beams from the sledge to form a cross, which he placed on the top. The following day he read the burial service.
Output (English): What did Mawson construct a rough cairn from snow blocks to cover?