instruction:
In this task, you are given a question and a context passage. You have to answer the question based on the given passage.
question:
Which of the following is NOT a goal of phorphor LED development: higher light output, optical losses, or higher operation temperatures?, Context: Among the challenges being faced to improve the efficiency of LED-based white light sources is the development of more efficient phosphors. As of 2010, the most efficient yellow phosphor is still the YAG phosphor, with less than 10% Stoke shift loss. Losses attributable to internal optical losses due to re-absorption in the LED chip and in the LED packaging itself account typically for another 10% to 30% of efficiency loss. Currently, in the area of phosphor LED development, much effort is being spent on optimizing these devices to higher light output and higher operation temperatures. For instance, the efficiency can be raised by adapting better package design or by using a more suitable type of phosphor. Conformal coating process is frequently used to address the issue of varying phosphor thickness.
answer:
optical losses

question:
How do chruches of christ worship in song?, Context: Present-day Christian religious bodies known for conducting their worship services without musical accompaniment include some Presbyterian churches devoted to the regulative principle of worship, Old Regular Baptists, Primitive Baptists, Plymouth Brethren, Churches of Christ, the Old German Baptist Brethren, Doukhobors the Byzantine Rite and the Amish, Old Order Mennonites and Conservative Mennonites. Certain high church services and other musical events in liturgical churches (such as the Roman Catholic Mass and the Lutheran Divine Service) may be a cappella, a practice remaining from apostolic times. Many Mennonites also conduct some or all of their services without instruments. Sacred Harp, a type of folk music, is an a cappella style of religious singing with shape notes, usually sung at singing conventions.
answer:
without musical accompaniment

question:
Apollo had a?, Context: A non-Greek origin of Apollo has long been assumed in scholarship. The name of Apollo's mother Leto has Lydian origin, and she was worshipped on the coasts of Asia Minor. The inspiration oracular cult was probably introduced into Greece from Anatolia, which is the origin of Sibyl, and where existed some of the oldest oracular shrines. Omens, symbols, purifications, and exorcisms appear in old Assyro-Babylonian texts, and these rituals were spread into the empire of the Hittites. In a Hittite text is mentioned that the king invited a Babylonian priestess for a certain "purification".
answer:
mother