instruction:
This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.
question:
Passage: The Chief Deputy Whip is the primary assistant to the whip, who is the chief vote counter for his or her party. The current chief deputy majority whip is Republican Patrick McHenry. Within the House Republican Conference, the chief deputy whip is the highest appointed position and often a launching pad for future positions in the House Leadership. The House Democratic Conference has multiple chief deputy whips, led by a Senior Chief Deputy Whip, which is the highest appointed position within the House Democratic Caucus. The current senior chief deputy minority whip, John Lewis, has held his post since 1991. Question: How long has democratic leader of whips held position?
answer:
senior chief deputy minority whip, John Lewis, has held his post since 1991


question:
Passage: Reflections generally affect polarization. For radio waves, one important reflector is the ionosphere which can change the wave's polarization. Thus for signals received following reflection by the ionosphere (a skywave), a consistent polarization cannot be expected. For line-of-sight communications or ground wave propagation, horizontally or vertically polarized transmissions generally remain in about the same polarization state at the receiving location. Matching the receiving antenna's polarization to that of the transmitter can make a very substantial difference in received signal strength. Question: What reflector can change the waves polarization?
answer:
ionosphere


question:
Passage: Molecules of carbohydrates and fats consist of carbon, hydrogen, and oxygen atoms. Carbohydrates range from simple monosaccharides (glucose, fructose, galactose) to complex polysaccharides (starch). Fats are triglycerides, made of assorted fatty acid monomers bound to a glycerol backbone. Some fatty acids, but not all, are essential in the diet: they cannot be synthesized in the body. Protein molecules contain nitrogen atoms in addition to carbon, oxygen, and hydrogen. The fundamental components of protein are nitrogen-containing amino acids, some of which are essential in the sense that humans cannot make them internally. Some of the amino acids are convertible (with the expenditure of energy) to glucose and can be used for energy production, just as ordinary glucose, in a process known as gluconeogenesis. By breaking down existing protein, the carbon skeleton of the various amino acids can be metabolized to intermediates in cellular respiration; the remaining ammonia is discarded primarily as urea in urine. This occurs normally only during prolonged starvation. Question: Which element do the amino acids that make up the core component of protein have in common?
answer:

nitrogen