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.

[Q]: 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: how does something stabilize something?
[A]: by varying the optical path to the sensor


[Q]: Sentence: Zane has hosted several Acid Test parties since then . 
 Question: when has someone hosted something?
[A]: since then


[Q]: Sentence: The psychological impact of this first transformation caused Beast to experience short-term amnesia and also made it difficult for him to control his animalistic instincts , which would cause him to slip into an uncontrollable berserker rage during combat . 
 Question: why would someone slip?
[A]:
The psychological impact of this first transformation caused Beast to experience short-term amnesia and also made it difficult for him to control his animalistic instincts