to use one's head

to use / to employ / to make use of, to apply / to spend

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

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

need, necessity

needed, necessary

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

use one thing for many purposes / work someone hard

頭: head

unsolved, unresolved