insoluble

a.(问题等)不能解决的；不能溶解的

insincere, insincerely, insincerity, insinuate, insinuation, insipid, insipidity, insipidly, insist, insist on sth. (doing sth.), insist upon, insistence, insistent, insistently, insofar, insofar as, insole, insolence, insolent, insolently, insolvency, insolvent, insomnia, insomniac, insomuch, insouciance, insouciant, Insp, inspect, inspection, inspector, inspector of taxes (also tax inspector), inspectorate, inspiration, inspirational, inspire, inspired, inspiring, Inst, instability,