instruction:
This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.
question:
Passage: Early Presbyterians were careful to distinguish between the "church," which referred the members, and the "meeting house," which was the building in which the church met. Until the late 19th century, very few Presbyterians ever referred to their buildings as "churches." Presbyterians believed that meeting-houses (now called churches) are buildings to support the worship of God. The decor in some instances was austere so as not to detract from worship. Early Presbyterian meeting-houses were extremely plain. No stained glass, no elaborate furnishings, and no images were to be found in the meeting-house. The pulpit, often raised so as only to be accessible by a staircase, was the centerpiece of the building.
answer:
What was the building where the images met called?


question:
Passage: Sichuan came under the firm control of a Chinese central government during the Sui dynasty, but it was during the subsequent Tang dynasty where Sichuan regained its previous political and cultural prominence for which it was known during the Han. Chengdu became nationally known as a supplier of armies and the home of Du Fu, who is sometimes called China's greatest poet. During the An Lushan Rebellion (755-763), Emperor Xuanzong of Tang fled from Chang'an to Sichuan. The region was torn by constant warfare and economic distress as it was besieged by the Tibetan Empire.
answer:
Who regained their prominence under the Sui dynasty?


question:
Passage: Most types of capacitor include a dielectric spacer, which increases their capacitance. These dielectrics are most often insulators. However, low capacitance devices are available with a vacuum between their plates, which allows extremely high voltage operation and low losses. Variable capacitors with their plates open to the atmosphere were commonly used in radio tuning circuits. Later designs use polymer foil dielectric between the moving and stationary plates, with no significant air space between them.
answer:

What do many capacitors contain that lower the capacitance?