In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

[Q]: What needs consistency?, Context: The simplest valve gears give events of fixed length during the engine cycle and often make the engine rotate in only one direction. Most however have a reversing mechanism which additionally can provide means for saving steam as speed and momentum are gained by gradually "shortening the cutoff" or rather, shortening the admission event; this in turn proportionately lengthens the expansion period. However, as one and the same valve usually controls both steam flows, a short cutoff at admission adversely affects the exhaust and compression periods which should ideally always be kept fairly constant; if the exhaust event is too brief, the totality of the exhaust steam cannot evacuate the cylinder, choking it and giving excessive compression ("kick back").[citation needed]
[A]: exhaust and compression periods


[Q]: Which character in Orwell's novel is represented by IBM?, Context: After the Lisa's announcement, John Dvorak discussed rumors of a mysterious "MacIntosh" project at Apple in February 1983. The company announced the Macintosh 128K—manufactured at an Apple factory in Fremont, California—in October 1983, followed by an 18-page brochure included with various magazines in December. The Macintosh was introduced by a US$1.5 million Ridley Scott television commercial, "1984". It most notably aired during the third quarter of Super Bowl XVIII on January 22, 1984, and is now considered a "watershed event" and a "masterpiece." Regis McKenna called the ad "more successful than the Mac itself." "1984" used an unnamed heroine to represent the coming of the Macintosh (indicated by a Picasso-style picture of the computer on her white tank top) as a means of saving humanity from the "conformity" of IBM's attempts to dominate the computer industry. The ad alludes to George Orwell's novel, Nineteen Eighty-Four, which described a dystopian future ruled by a televised "Big Brother."
[A]: Big Brother


[Q]: Which 31 day period is when the cost of fuel got worse?, Context: In August 2007, an increase in the price of diesel and petrol led to Saffron Revolution led by Buddhist monks that were dealt with harshly by the government. The government cracked down on them on 26 September 2007. The crackdown was harsh, with reports of barricades at the Shwedagon Pagoda and monks killed. There were also rumours of disagreement within the Burmese armed forces, but none was confirmed. The military crackdown against unarmed protesters was widely condemned as part of the International reactions to the Saffron Revolution and led to an increase in economic sanctions against the Burmese Government.
[A]:
August 2007