technical

(attributive) something that is technical / (attributive) something that involves technology

needed, necessary

need, necessity

knowledge

speciality/specialty; subject of study; subject of expertise; area of interest; profession

solution, settlement / (music) Progression from dissonance to consonance; a chord to which such progression is made; resolution

(transitive) solve, resolve, settle (a problem, a trouble, a criminal case) / (intransitive) be solved, be settled / (intransitive) can be solved; be soluble

question, problem on homework etc. / a question; a matter (of time etc.) / a problem (something that needs to be dealt with); a trouble / an issue; a matter

scientific knowledge