Identify https://cdn.thingiverse.com/as....sets/a6/9e/38/13/05/ the hazards of breathing an hypoxic trimix on the https://cdn.thingiverse.com/as....sets/17/61/bb/8c/e4/ surface, and what https://cdn.thingiverse.com/as....sets/b6/9e/63/ae/0c/ ... “Comfort Zone” is described https://cdn.thingiverse.com/as....sets/40/9d/29/e5/71/ in https://cdn.thingiverse.com/as....sets/86/a3/48/f7/9a/ the https://cdn.thingiverse.com/as....sets/d9/f5/6c/69/a4/ Advanced Student Manual as https://cdn.thingiverse.com/as....sets/0f/79/be/1b/e9/ a https://cdn.thingiverse.com/as....sets/24/99/16/76/51/ “planning tool” ... 420b4ec2cf .