official rate的用法和樣例：
例句
- Since the beginning of the year, there have been sharp drops in the dollar-yen conversion rate.
年初以來，美元對日元的匯價一路下瀉。 - The yuans movements have in fact started to track more closely estimates of its effective exchange rate, or the currencys overall value against all of Chinas trading partners.
實際上，人民幣走勢已經開始更緊密地追隨其有效匯率的估值，有效匯率即人民幣兌中國所有貿易夥伴國貨幣的總體匯價。 - Usury is interest in excess of a legal rate.
高利貸是指超過法定利率取息。
