1)Rappelling means the process of descending a rope
tied or fixed to a body with different knot techniques.
Rock climbers use rappelling to return to the base.
Rescue teams use it to access places which are flooded
or on fire.Military or police use it to raid buildings from helicoptors.
2)Synaesthesia is a condition where the various senses
intermingle.In music, they perceive colours in notes
others taste words or shapes.Synaesthesia is caused by
”cross–wiring” between the regions of the brain
responsible for processing different kinds of sensory signals.