investigate

v.调查，调查研究

invariance, invasion, invasive, invective, inveigh, inveigle, invent, invention, inventive, inventor, inventory, inverse, inversely, inversion, invert, invertebrate, inverted, inverted commas, inverted snob, invest, investigation, investigative, investigator, investiture, investment, investor, inveterate, inveterately, invidious, invidiously, invidiousness, invigilate, invigilation, invigilator, invigorate, invigorating, invigoratingly, invigoration, invincibility, invincible,