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.
One example is below.
Q: 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.
A: Who believes Fagin's gang make wallets and handkerchiefs?.
Rationale: 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.
Q: Passage: Grunge is generally characterized by a sludgy electric guitar sound with a "thick" middle register and rolled-off treble tone and a high level of distortion and fuzz, typically created with small 1970s-style stompbox pedals, with some guitarists chaining several fuzz pedals together and plugging them into a tube amplifier and speaker cabinet. Grunge guitarists use very loud Marshall guitar amplifiers  and some used powerful Mesa-Boogie amplifiers, including Kurt Cobain and Dave Grohl (the latter in early, grunge-oriented Foo Fighters songs ). Grunge has been called the rock genre with the most "lugubrious sound"; the use of heavy distortion and loud amps has been compared to a massive "buildup of sonic fog". or even dismissed as "noise" by one critic. As with metal and punk, a key part of grunge's sound is very distorted power chords played on the electric guitar.Whereas metal guitarists' overdriven sound generally comes from a combination of overdriven amplifiers and distortion pedals, grunge guitarists typically got all of their "dirty" sound from overdrive and fuzz pedals, with the amp just used to make the sound louder. Grunge guitarists tended to use the Fender Twin Reverb and the Fender Champion 100 combo amps (Cobain used both of these amps). The use of pedals by grunge guitarists was a move away from the expensive, studio-grade rackmount effects units used in other rock genres. The positive way that grunge bands viewed stompbox pedals can be seen in Mudhoney's use of the name of two overdrive pedals, the Univox Super-Fuzz and the Big Muff, in the title of their "debut EP Superfuzz Bigmuff".  In the song Mudride, the band's guitars were said to have "growled malevolently" through its "Cro-magnon slog".
A:
What two brands of amplifiers do grunge guitarists use?