<prompt> True about Boyles apparatus a Continuous flow machineb Liquid anesthetic vapours not usedc Resistance very highd Resistance lowbcadab  <response>: Boyles machine operates on the continuous flow principle, where gas flows all the time during inspiration and expiration.Vaporizer contain a volatile inhalation anesthetic agent in liquid form which is vaporized before being mixed with gaseous mixture.Resistance to intermittent gas flow should be very low. 