Input: Article: Carbon metabolism in bacteria is either heterotrophic, where organic carbon compounds are used as carbon sources, or autotrophic, meaning that cellular carbon is obtained by fixing carbon dioxide. Heterotrophic bacteria include parasitic types. Typical autotrophic bacteria are phototrophic cyanobacteria, green sulfur-bacteria and some purple bacteria, but also many chemolithotrophic species, such as nitrifying or sulfur-oxidising bacteria. Energy metabolism of bacteria is either based on phototrophy, the use of light through photosynthesis, or based on chemotrophy, the use of chemical substances for energy, which are mostly oxidised at the expense of oxygen or alternative electron acceptors (aerobic/anaerobic respiration).

Now answer this question: What is chemotrophy ?

Output: the use of chemical substances for energy

Input: Article: Bitumen was used in early photographic technology. In 1826 or 1827, it was used by French scientist Joseph Nicephore Niepce to make the oldest surviving photograph from nature. The bitumen was thinly coated onto a pewter plate which was then exposed in a camera. Exposure to light hardened the bitumen and made it insoluble, so that when it was subsequently rinsed with a solvent only the sufficiently light-struck areas remained. Many hours of exposure in the camera were required, making bitumen impractical for ordinary photography, but from the 1850s to the 1920s it was in common use as a photoresist in the production of printing plates for various photomechanical printing processes.[not in citation given]

Now answer this question: During what period was bitumen used in printing processes?

Output: 1850s to the 1920s

Input: Article: One problem with these assignments is admixture. Many people have a highly varied ancestry. For example, in the United States, colonial and early federal history were periods of numerous interracial relationships, both outside and inside slavery. This has resulted in a majority of people who identify as African American having some European ancestors. Similarly, many people who identify as white have some African ancestors. In a survey in a northeastern U.S. university of college students who identified as "white", about 30% were estimated to have up to 10% African ancestry.

Now answer this question: How many people have a varied ancestry?

Output:
Many