The________ of currency of many Asian countries to US dollar greatly lowered in the recent financial crisis．
A.rateB.exchangeC.changeD.proportion在线课程A
A rate比率，速率。句意为“在最近的金融危机中．亚洲许多国家的货币对美元的汇率都降低了许多”。exchange交换；change改变：pro-portion 比例。