<prompt> Eustachian tube passes betweenSuperior and middle constrictorsAbove superior constrictorMiddle and inferior constrictorBelow inferior constrictor  <response>: The auditory tube passes between the large gap between the upper concave border of the superior constrictor and the base of the skull is semilunar and is known as the sinus of Morgagni. It is closed by the upper strong pa of the pharyngobasilar fascia. Ref: BD Chaurasias HUMAN ANATOMY, Volume 3, 4th edition. 