Context and question: One of the most spectacular examples of obligate mutualism is between the siboglinid tube worms and symbiotic bacteria that live at hydrothermal vents and cold seeps. The worm has no digestive tract and is wholly reliant on its internal symbionts for nutrition. The bacteria oxidize either hydrogen sulfide or methane, which the host supplies to them. These worms were discovered in the late 1980s at the hydrothermal vents near the Galapagos Islands and have since been found at deep-sea hydrothermal vents and cold seeps in all of the world's oceans.
From where do the host obtain the hydrogen sulfide or methane?
Answer: unanswerable
Context and question: In the mid to late 1990s many higher-end AV receivers included the demodulator circuit specifically for the LaserDisc players RF modulated Dolby Digital AC-3 signal. By the late 1990s with LaserDisc players and disc sales declining due to DVD's growing popularity the AV receiver manufacturers removed the demodulator circuit. Although DVD players were capable of playing Dolby Digital tracks, the signal out of DVD player were not in a modulated form and not compatible with the inputs designed for LaserDisc AC-3. Outboard demodulators were available for a period that convert the AC-3 signal to standard Dolby Digital signal that was compatible with the standard Dolby Digital/PCM inputs on capable AV receivers. Another type marketed by Onkyo and others converted the RF AC-3 signal to 6-channel analog audio.
Did all AV receivers carry the demodulator circuits necessary for LaserDiscs, or only high-end models?
Answer: higher-end
Context and question: It is admitted that the doctrine as defined by Pius IX was not explicitly mooted before the 12th century. It is also agreed that "no direct or categorical and stringent proof of the dogma can be brought forward from Scripture". But it is claimed that the doctrine is implicitly contained in the teaching of the Fathers. Their expressions on the subject of the sinlessness of Mary are, it is pointed out, so ample and so absolute that they must be taken to include original sin as well as actual. Thus in the first five centuries such epithets as "in every respect holy", "in all things unstained", "super-innocent", and "singularly holy" are applied to her; she is compared to Eve before the fall, as ancestress of a redeemed people; she is "the earth before it was accursed". The well-known words of St. Augustine (d. 430) may be cited: "As regards the mother of God," he says, "I will not allow any question whatever of sin." It is true that he is here speaking directly of actual or personal sin. But his argument is that all men are sinners; that they are so through original depravity; that this original depravity may be overcome by the grace of God, and he adds that he does not know but that Mary may have had sufficient grace to overcome sin "of every sort" (omni ex parte).
Who is not sure that Mary had sufficient grace to overcome sin?
Answer:
unanswerable