Why does the top of a liquid usually have a flat surface

Liquids fill the shape of any container they are in. ... The top of a liquid will usually have a flat surface. That flat surface is the result of gravity pulling on the liquid molecules.

This is what i found “in a gas turbine engine, the combustor or combustion chamber is fed high pressure air by the compression system. early gas turbine engines used a single chamber known as a can type combustor. today three main configurations exist: can, annular and cannular (also referred to as can-annular tubo-annular).” i hope this you for what your looking for. can you plz mark me brainliest?