An example of slow combustion is ______.

An example of slow combustion is respiration. Hydrocarbons react with oxygen to produce carbon dioxide gas, water vapour, and energy in the form of heat and light in combustion.

${\mathrm{C}}_{6 }{\mathrm{H}}_6{\mathrm{O}}_6 +6 {\mathrm{O}}_2 \to 6{\mathrm{CO}}_2 + 6{\mathrm{H}}_2\mathrm{O} + \mathrm{Energy}$ 

Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase.

Precipitation is any liquid or frozen water that forms in the atmosphere and falls back to the Earth.  

Digestion refers to the breakdown of food into smaller components that can be absorbed into the bloodstream.