What does the word deficiency mean a. need b. excess c. problem d. lack

Answer is D! Ex. Andy has a Vitamin A deficiency.

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?