A unit of weight in the U.S. Customary System,an avoirdupois unit equal to 437.5 grains(28.35 grams).是什么意思_A unit of weight in the U.S. Customary System,an avoirdupois unit equal to 437.5 grains(28.35 grams).在线翻译_英语_读音_用法_例句