analyze answer appraise ascertain assess assort assure bolt bottom catalog categorize certify cinch clarify class classify clear up clinch cogitate collate contradistinguish cordon cordon off crack cull out debug decide decipher decode demarcate demark determine differentiate discriminate disembroil disentangle disintricate disinvolve dismiss all doubt distinguish divide divine do dope dope out draw the line ensure establish evaluate excogitate explain factor fathom figure out find out find the answer find the solution fix gauge get get at get right ghettoize gin give thought to gradate grade group guess guess right have it hit it identify insulate insure interpret isolate keep apart keep aside lay aside make certain make no doubt make no mistake make out make sure make sure of mark the interface nail down open the lock pick out plumb psych psych out put aside puzzle out quarantine rank ravel ravel out reason out reassure remove all doubt resolve riddle screen screen out seclude see that see to it segregate select separate set a limit set apart set aside set at rest set off settle sever severalize sieve sieve out sift sift out size solve sort split hairs subdivide subordinate subtilize think about think out think through thrash thrash out thresh unbraid unclutter uncoil undo unknot unlock unmix unravel unriddle unscramble unsnarl untangle unthread untwine untwist unweave unwind weigh winnow work work out