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

Ex Input:
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.

Ex Output:
without musical accompaniment

Ex Input:
When did the first world war occur?, Context: The war has been described as the first "world war", although this label was also given to various earlier conflicts like the Eighty Years' War, the Thirty Years' War, the War of the Spanish Succession and the War of the Austrian Succession, and to later conflicts like the Napoleonic Wars. The term "Second Hundred Years' War" has been used in order to describe the almost continuous level of world-wide conflict during the entire 18th century, reminiscent of the more famous and compact struggle of the 14th century.

Ex Output:
18th century

Ex Input:
What is abstract theory with basis in reality?, Context: Whitehead did not begin his career as a philosopher. In fact, he never had any formal training in philosophy beyond his undergraduate education. Early in his life he showed great interest in and respect for philosophy and metaphysics, but it is evident that he considered himself a rank amateur. In one letter to his friend and former student Bertrand Russell, after discussing whether science aimed to be explanatory or merely descriptive, he wrote: "This further question lands us in the ocean of metaphysic, onto which my profound ignorance of that science forbids me to enter." Ironically, in later life Whitehead would become one of the 20th century's foremost metaphysicians.

Ex Output:
metaphysic