inner tube

inflatable rubber tube inside a tyre （轮胎的）内胎.

inkling, inkstand, inky, inlaid, inland, Inland Revenue, inlay, inlet, inmate, inmost, inn, Inn of Court, inn-keeper, innards, innate, innately, inner, inner circle, inner city, inner lane, innermost, inning, innings, innkeeper, innocence, innocent, innocently, innocuous, innocuously, innocuousness, innovate, innovation, innovative, innovator, innuendo, Innuit (also Inuit), innumerable, innumeracy, innumerate, inoculate,