conce ionary rateconcessionary ratefavorable ratepreference ratepremium ratesrate of concession优惠: preferential; favourable率: rate; ratio; proportion大户优惠率: quantum allowance固定优惠率: fixed conce ionary rate; fixed concessionary rate关税优惠率: tariff concession rate; tariffconce ionrate下载手机词典可随时随地查词查翻译