invigilate (v.) invidious (adj.) invictus inviable (adj.) inveterate (adj.) inveteracy (n.) investor (n.) investment (n.) investiture (n.) investigator (n.) investigative (adj.) investigation (n.) investigating v. 调查；审查（investigate的ing形式）investigates v.调查；研究investigated v.调查；研究investigate (v.) investigate vt.调查vi.作调查investigable (adj.) invest (v.) invertebrate (adj.)