Teacher:In this task, you are given a sentence and a verb from the sentence. Your task is to generate a set of wh-questions starting with who, what, when, where, why, how, how much. The generated questions must contain the verb and the answers to these questions are phrases in the input sentence. The answer to the questions is associated with a specific semantic role. The answer to these questions is associated with a specific semantic role. The questions must use pronouns instead of direct nouns that could be used to refer to various roles present in the sentence. Construct a question in such a way that (i) it is unambiguous, (ii) its answer is unique (iii) its answer is a continuous text span from the paragraph.
Teacher: Now, understand the problem? Solve this instance: 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 . 
 Verb: abbreviated
Student:
what is  abbreviated?