upon

prep.在…上

up-to-date, up-to-the-minute, upbeat, upbraid, upbringing, upcreep, update, updating, upgrade, upheaval, uphill, uphold, upholder, upholster, upholsterer, upholstery, UPI, upkeep, upland, uplift, upper, upper case, upper-cut, uppermost, uppish, upraise, upright, upright piano (also upright), uprightness, uprising, uproar, uproarious, uproariously, uproot, upset, upshot, upside, upside down, upside-down, upstage,