The following are multiple choice questions (with answers) about medical knowledge.   **Question:** All of the following about use of aerotor hand piece are false except:   (A) The sound frequency greater than 75 decibel (dB) causes damage to the ear   (B) The frequency of rotation of bur is 6000-8000rpm   (C) It will harm more in elderly than very young   (D) Its use in younger teeth is contraindicated.
['(A) The sound frequency greater than 75 decibel (dB) causes damage to the ear <> answer', 'The following are multiple choice questions (with answers) about medical knowledge. <> instruction', '(A) The sound frequency greater than 75 decibel (dB) causes damage to the ear \n (B) The frequency of rotation of bur is 6000-8000rpm \n (C) It will harm more in elderly than very young \n (D) Its use in younger teeth is contraindicated. <> possible answers', '  All of the following about use of aerotor hand piece are false except: <> context@']