<prompt> Which of the following is not a derivative of the middle ear cleft?Semicircular canalMastoid air cellTympanic cavityEustachian tube  <response>: The middle-ear cleft in the temporal bone includesEustachian tubeThe middle ear tympanic cavityAditus which leads posteriorly to the mastoid antrum and air cellsRef: PL Dhingra, Diseases of Ear, Nose Throat, 7th edition, pg no. 5 