upbeat

adj (fig 比喻) optimistic or cheerful 乐观的; 快乐的.

unworthily, unworthiness, unworthy, unwound, unwritten, unyielding, up, up and doing, up and down, up in arms, up to, up to date, up to time, up-, up-and-coming, up-country, up-end, up-market, up-to-date, up-to-the-minute, upbraid, upbringing, upcreep, update, updating, upgrade, upheaval, uphill, uphold, upholder, upholster, upholsterer, upholstery, UPI, upkeep, upland, uplift, upon, upper, upper case,