Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

Example Input: Carbon is one of the most common elements found in living organisms. Chains of carbon molecules form the backbones of many organic molecules, such as carbohydrates, proteins, and lipids. Carbon is constantly cycling between living organisms and the atmosphere ( Figure 1.1). The cycling of carbon occurs through the carbon cycle. Living organisms cannot make their own carbon, so how is carbon incorporated into living organisms? In the atmosphere, carbon is in the form of carbon dioxide gas (CO2 ). Recall that plants and other producers capture the carbon dioxide and convert it to glucose (C6 H12 O6 ) through the process of photosynthesis. Then as animals eat plants or other animals, they gain the carbon from those organisms. The chemical equation of photosynthesis is 6CO2 + 6H2 O C6 H12 O6 + 6O2 . How does this carbon in living things end up back in the atmosphere? Remember that we breathe out carbon dioxide. This carbon dioxide is generated through the process of cellular respiration, which has the reverse chemical reaction as photosynthesis. That means when our cells burn food (glucose) for energy, carbon dioxide is released. We, like all animals, exhale this carbon dioxide and return it back to the atmosphere. Also, carbon is released to the atmosphere as an organism dies and decomposes. Cellular respiration and photosynthesis can be described as a cycle, as one uses carbon dioxide (and water) and makes oxygen (and glucose), and the other uses oxygen (and glucose) and makes carbon dioxide (and water). The carbon cycle. The cycling of car- bon dioxide in photosynthesis and cellular respiration are main components of the carbon cycle. Carbon is also returned to the atmosphere by the burning of organic matter (combustion) and fossil fuels and decomposition of organic matter. Millions of years ago, there were so many dead plants and animals that they could not completely decompose before they were buried. They were covered over by soil or sand, tar or ice. These dead plants and animals are organic matter made out of cells full of carbon-containing organic compounds (carbohydrates, lipids, proteins and nucleic acids). What happened to all this carbon? When organic matter is under pressure for millions of years, it forms fossil fuels. Fossil fuels are coal, oil, and natural gas. When humans dig up and use fossil fuels, we have an impact on the carbon cycle ( Figure 1.2). This carbon is not recycled until it is used by humans. The burning of fossil fuels releases more carbon dioxide into the atmosphere than is used by photosynthesis. So, there is more carbon dioxide entering the atmosphere than is coming out of it. Carbon dioxide is known as a greenhouse gas, since it lets in light energy but does not let heat escape, much like the panes of a greenhouse. The increase of greenhouse gasses in the atmosphere is contributing to a global rise in Earths temperature, known as global warming or global climate change.
Example Output: when organisms die, what process returns their carbon back into the atmosphere?

Example Input: Contrary to earlier beliefs, viruses are not the smallest causative agents of infectious diseases. Single-stranded RNAs as small as 246 nucleotides exist in certain higher plants and cause more than a dozen crop diseases. These RNAs have been termed viroids. Despite their extremely limited information content, viroids replicate autonomously in susceptible cells--that is, they do not require helper functions from simultaneously replicating conventional viruses. Viroids are covalently closed circular molecules with a characteristic rodlike secondary structure in which short helical regions are interrupted by internal and bulge loops. Viroids are not translated; they are replicated by a host enzyme (or enzymes) (probably RNA polymerase II) via oligomeric RNA intermediates by a rolling circle mechanism. Viroidlike satellite RNAs resemble viroids in size and molecular structure, but are found within the capsids of specific helper viruses on which they depend for their own replication. These RNAs are of great interest to molecular biology for at least two reasons: 1) they are the smallest and simplest replicating molecules known, and 2) they may represent living fossils of precellular evolution in a hypothetical RNA world.
Example Output: Which are the smallest known subviral pathogens of plants?

Example Input: In follicular lymphoma, a chromosomal translocation commonly occurs between the fourteenth and the eighteenth chromosomes -- t(14;18) -- which places the Bcl-2 gene from chromosome 18 next to the immunoglobulin heavy chain locus on chromosome 14.
Example Output:
Which chromosone can you find Bcl-2?