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.

Input: Consider Input: Passage: Cultural depictions of dogs in art extend back thousands of years to when dogs were portrayed on the walls of caves. Representations of dogs became more elaborate as individual breeds evolved and the relationships between human and canine developed. Hunting scenes were popular in the Middle Ages and the Renaissance. Dogs were depicted to symbolize guidance, protection, loyalty, fidelity, faithfulness, watchfulness, and love. Question: Thousands of years ago, dogs were depicted on the walls of what?

Output: caves.


Input: Consider Input: Passage: In the Romantic era, the modern piano, with a more powerful, sustained tone and a wider range took over from the more delicate-sounding fortepiano. In the orchestra, the existing Classical instruments and sections were retained (string section, woodwinds, brass and percussion), but these sections were typically expanded to make a fuller, bigger sound. For example, while a Baroque orchestra may have had two double bass players, a Romantic orchestra could have as many as ten. "As music grew more expressive, the standard orchestral palette just wasn't rich enough for many Romantic composers."  New woodwind instruments were added, such as the contrabassoon, bass clarinet and piccolo and new percussion instruments were added, including xylophones, drums, celestes (a bell-like keyboard instrument), large orchestral harps, bells, and triangles  and even wind machines for sound effects. Question: What is a celestes?

Output: a bell-like keyboard instrument


Input: Consider Input: Passage: Efforts to identify the origins of Ashkenazi Jews through DNA analysis began in the 1990s. Currently, there are three types of genetic origin testing, autosomal DNA (atDNA), mitochondrial DNA (mtDNA), and Y-chromosomal DNA (Y-DNA). Autosomal DNA is a mixture from an individual's entire ancestry, Y-DNA shows a male's lineage only along his strict-paternal line, mtDNA shows any person's lineage only along the strict-maternal line. Genome-wide association studies have also been employed to yield findings relevant to genetic origins. Question: How many types of genetic origin testing currently exist?


Output: three types of genetic origin testing