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: The ice must be cut through, broken up, or melted.  Tools can be directly pushed into snow and firn (snow that is compressed, but not yet turned to ice, which typically happens at a depth of 60 metres (200 ft) to 120 metres (390 ft)); this method is not effective in ice, but it is perfectly adequate for obtaining samples from the uppermost layers.  For ice, two options are percussion drilling and rotary drilling.  Percussion drilling uses a sharp tool such as a chisel, which strikes the ice to fracture and fragment it.  More common are rotary cutting tools, which have a rotating blade or set of blades at the bottom of the borehole to cut away the ice.  For small tools the rotation can be provided by hand, using a T-handle or a carpenter's brace.  Some tools can also be set up to make use of ordinary household power drills, or they may include a motor to drive the rotation.  If the torque is supplied from the surface, then the entire drill string must be rigid so that it can be rotated; but it is also possible to place a motor just above the bottom of the drill string, and have it supply power directly to the drill bit.If the ice is to be melted instead of cut, then heat must be generated.  An electrical heater built into the drill string can heat the ice directly, or it can heat the material it is embedded in, which in turn heats the ice.  Heat can also be sent down the drill string; hot water or steam pumped down from the surface can be used to heat a metal drillhead, or the water or steam can be allowed to emerge from the drillhead and melt the ice directly.  In at least one case a drilling project experimented with heating the drillhead on the surface, and then lowering it into the hole.Many ice drilling locations are very difficult to access, and drills must be designed so that they can be transported to the drill site.  The equipment should be as light and portable as possible.  It is helpful if the equipment can be broken down so that the individual components can be carried separately, thus reducing the burden for hand-carrying, if required.  Fuel, for steam or hot water drills, or for a generator to provide power, must also be transported, and this weight has to be taken into account as well.
Student:
What object's weight has to be taken into account as well?