<prompt> In nasal endoscopy Eustachian tube is examined at?1st pass2nd pass3rd pass4th pass  <response>: Ans. isai.e., 1st passNasal endoscopy is done in three passes :-First Pass: Examination of nasal cavity, nasopharynx, opening of eustachian tube, walls of nasopharynx, upper surface of soft palate and uvula, opening of eustachian tube of opposite side opening of nasolacrimal duct and inferior meatus. 