In this task, you are given a sentence and question which can be answered using the sentence. Your task is to answer the question using the information from the sentence. The answer to the question is unique and it is a continuous text span from the sentence.

Sentence: An `` optical image stabilizer '' , often abbreviated OIS , IS , or OS , is a mechanism used in a still camera or video camera that stabilizes the recorded image by varying the optical path to the sensor . 
 Question: what is something used  in?
a still camera or video camera ### a still camera ### video camera

Sentence: `` American Guru : A Story of Love , Betrayal and Healing '' , by William Yenner and other former Cohen student contributors , allege authoritarianism , financial manipulation , physical and psychological abuse in Cohen 's community , and discusses the challenges of healing after leaving the community . 
 Question: who are  discussing something?
William Yenner and other former Cohen student contributors

Sentence: Although the area was known for its healthy waters at least since the late Middle Ages , the spa was officially founded in 1769 . 
 Question: when was something known  for something?

since the late Middle Ages