In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Q: What is a prerequisite for weight to play a factor in conductivity?, Context: While inert gas reduces filament evaporation, it also conducts heat from the filament, thereby cooling the filament and reducing efficiency. At constant pressure and temperature, the thermal conductivity of a gas depends upon the molecular weight of the gas and the cross sectional area of the gas molecules. Higher molecular weight gasses have lower thermal conductivity, because both the molecular weight is higher and also the cross sectional area is higher. Xenon gas improves efficiency because of its high molecular weight, but is also more expensive, so its use is limited to smaller lamps.

A: constant pressure and temperature
****
Q: What happened to Santa Pudenziana?, Context: With the building of Christian basilicas in the late 4th century, wall and ceiling mosaics were adopted for Christian uses. The earliest examples of Christian basilicas have not survived, but the mosaics of Santa Constanza and Santa Pudenziana, both from the 4th century, still exist. The winemaking putti in the ambulatory of Santa Constanza still follow the classical tradition in that they represent the feast of Bacchus, which symbolizes transformation or change, and are thus appropriate for a mausoleum, the original function of this building. In another great Constantinian basilica, the Church of the Nativity in Bethlehem the original mosaic floor with typical Roman geometric motifs is partially preserved. The so-called Tomb of the Julii, near the crypt beneath St Peter's Basilica, is a 4th-century vaulted tomb with wall and ceiling mosaics that are given Christian interpretations. The Rotunda of Galerius in Thessaloniki, converted into a Christian church during the course of the 4th century, was embellished with very high artistic quality mosaics. Only fragments survive of the original decoration, especially a band depicting saints with hands raised in prayer, in front of complex architectural fantasies.

A: The Rotunda of Galerius in Thessaloniki
****
Q: How is whiteness established?, Context: The US racial or ethnic classification "black" refers to people with all possible kinds of skin pigmentation, from the darkest through to the very lightest skin colors, including albinos, if they are believed by others to have West African ancestry (in any discernible percentage), or to exhibit cultural traits associated with being "African American". As a result, in the United States the term "black people" is not an indicator of skin color or ethnic origin but is instead a socially based racial classification related to being African American, with a family history associated with institutionalized slavery. Relatively dark-skinned people can be classified as white if they fulfill other social criteria of "whiteness", and relatively light-skinned people can be classified as black if they fulfill the social criteria for "blackness" in a particular setting.

A:
social criteria
****