How is the manner of death determined in hanging and drowning?

Asphyxia — the oxygen's deprivation (the life's smothering): the mechanism's family — the air's passage blocked, the oxygen's exchange prevented, the neck's vessels compressed. The types(the exam's list):1. Hanging — the body's own weight on the ligature (the suspension's faces: the complete-vs- partial); the knot's position (the typical occipital — the atypical's variations); the ligature's groove (the furrow's direction: the upward-inverted-V).2. Strangulation — the external force on the neck (the ligature (the horizontal groove — the hanging's differential!) and the manual (the finger-marks — the bruises' ovals)).3. Suffocation — the environment's oxygen lack (the smothering (the obstruction: the pillow, the hand); the choking (the internal: the food, the foreign body); the confined-space (the gases)).4. Drowning — the water's drowning (the fresh-vs-salt faces; the "dry drowning" debates).5. The mechanical (traumatic) asphyxia — the crush (the chest's compression — the disaster's-and-crowd's deaths).6. The chemical asphyxiants — the gases (the carbon-monoxide, the cyanide — the toxicology's bridge).