Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

to investigate the origin characters of snore in simple snorers and provide the basis for its treatment.', 'Thirty-two simple snorers diagnosed by polysomnography were induced to sleep by propofol and dexmedetomidine, then we observed the vibration sites, pattern and concomitant collapse of soft tissue in pharyngeal cavity by nasendoscopy.', 'Thirteen cases showed palatal fluttering only, and 1 case showed vibration of epiglottis only. Six cases showed palatal fluttering with vibration of epiglottis, and 2 cases showed palatal fluttering with vibration of epiglottis and tongue base. Five cases showed palatal fluttering with vibration of pharyngeal lateral wall, and 5 cases showed palatal fluttering with vibration of lateral wall, epiglottis and tongue base together. Palate and pharyngeal lateral wall vibrated strongly and always collapsed with vibrating, but epiglottis and tongue base usually vibrated slightly and seldom collapsed.
Do [ The preliminary study of the origin characters of snore in simple snorers ]?