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 1972, the Presbyterian Church of England (PCofE) united with the Congregational Church in England and Wales to form the United Reformed Church (URC). Among the congregations the PCofE brought to the URC were Tunley (Lancashire), Aston Tirrold (Oxfordshire) and John Knox Presbyterian Church, Stepney, London (now part of Stepney Meeting House URC) these are among the sole survivors today of the English Presbyterian churches of the 17th century. The URC also has a presence in Scotland, mostly of former Congregationalist Churches. Two former Presbyterian congregations, St Columba's, Cambridge (founded in 1879), and St Columba's, Oxford (founded as a chaplaincy by the PCofE and the Church of Scotland in 1908 and as a congregation of the PCofE in 1929), continue as congregations of the URC and university chaplaincies of the Church of Scotland. Question: What are the two former Presbyterian congregations in England?

Output: St Columba's, Cambridge (founded in 1879), and St Columba's, Oxford

Input: Consider Input: Passage: Unaspirated or tenuis consonants are occasionally marked with the modifier letter for unaspiration , a superscript equal sign: t. Usually, however, unaspirated consonants are left unmarked: t. Question: What is the superscript equal sign?
Output: t